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NXP Semiconductors FXTH87E Reference Manual
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NXP Semiconductors FXTH87E Reference Manual

Family of tire pressure monitor sensors
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FXTH87E
FXTH87E, Family of Tire Pressure Monitor Sensors
Rev. 5.0 — 4 February 2019

1.1 Purpose

This reference manual describes the features, architecture, and programming model of
the FXTH87E family of devices.

1.2 Audience

This document is primarily for system architects and software application developers who
are using or considering use of the FXTH87E in a system.

1.3 Related documentation

The FXTH87E device features and operations are described in a variety of reference
manuals, user guides, and application notes. To find the most-current versions of these
documents:
1. Go to the FXTH87E page on NXP.com at:
2. Select the documentation tab and review the related documentation.
Contact NXP sales representatives for performance attributes such as electrical,
mechanical, and time-based characteristics.

2.1 General description

The FXTH87E is a small (7 x 7 mm), fully integrated tire pressure monitoring sensor
(TPMS). It also provides low transmitting power consumption, large customer memory
size and dual-axis accelerometer architecture. The FXTH87E TPMS solution integrates
an 8-bit microcontroller (MCU), pressure sensor, XZ-axis or Z-axis accelerometer and RF
transmitter.

2.2 Features and benefits

•
Long battery service life
•
Provided software for power optimization
•
Pin for pin electrical connections compatible with FXTH87-based customer applications
•
Included firmware subroutines compatible with FXTH87-based customer software
•
Pressure sensor with one of three calibrated pressure ranges
•
Temperature sensor
•
Optional XZ- or Z-axis accelerometer with adjustable offset option
•
Voltage reference measured by ADC10
Reference manual
http://www.nxp.com/FXTH87E

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Summary of Contents for NXP Semiconductors FXTH87E

  • Page 1: About This Document

    Product profile 2.1 General description The FXTH87E is a small (7 x 7 mm), fully integrated tire pressure monitoring sensor (TPMS). It also provides low transmitting power consumption, large customer memory size and dual-axis accelerometer architecture. The FXTH87E TPMS solution integrates an 8-bit microcontroller (MCU), pressure sensor, XZ-axis or Z-axis accelerometer and RF transmitter.

  • Page 2: Configuration Options

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors • Six-channel, 10-bit analog-to-digital converter (ADC10) with two external I/O inputs • 8-bit MCU – S08 Core with SIM and interrupt – 512 RAM – 16 KB FLASH – 64-byte, low-power, parameter registers •...

  • Page 3: Part Number Definition

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors 2.4 Part number definition a XTH87E b cc d T1 Table 2. Part number breakdown Code Option Description a = P (Prototype) a = F (Qualified) b = G (500 kPa range) b = H (900 kPa range)

  • Page 4: General Information

    FXTH87E, Family of Tire Pressure Monitor Sensors General Information 3.1 Overall block diagram The block diagram of the FXTH87E is shown in Figure 1. This diagram covers all the main blocks mentioned above and their main signal interactions. Power management controls and bus control signals are not shown in this block diagram for clarity.

  • Page 5: Multi-Chip Interface

    NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors 3.2 Multi-chip interface The FXTH87E contains two to three devices using the best process technology for each. • Microcontroller with accelerometer and pressure sensor interfaces, and RF transmitter (MCU) • Optional ranges on pressure transducers •...

  • Page 6: Reference Documents

    NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors 3.4 Reference documents The FXTH87E utilizes the standard product MC9S08 CPU core. For further details on the full capabilities of this core, refer to the HCS08 Family Reference Manual (HCS08RMV1). Pinning information This section describes the pin layout and general function of each pin.

  • Page 7: Pin Description

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors 4.2 Pin description Table 4. Pin description Symbol Description PTB1 General purpose I/O PTA2 General purpose I/O PTA1 General purpose I/O PTA0 General purpose I/O RESET External reset Digital circuit ground...

  • Page 8: Signal Properties

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors L1 and matching network optimized for specific PWB and R2 and antenna layout. Recommend recommended for 0603 minimum size for L1 and highest EMC resistance other matching network inductors for maximum efficiency.

  • Page 9: Vdd And Vss Pins

    4.4.5 RF pin The RF pin is the RF energy data supplied by the FXTH87E to an external antenna. FXTH87ERM All information provided in this document is subject to legal disclaimers.

  • Page 10: Xo, Xi Pins

    (BDM) to evaluate MCU code and to also transfer data to/from the internal memories. If the BKGD/PTA4 pin is held low when the FXTH87E comes out of a power- on reset the device will go into the ACTIVE BACKGROUND DEBUG mode (BDM).

  • Page 11: Reset Pin

    – STOP4: All internal circuits powered and full voltage regulation maintained for fastest recovery 5.2 RUN mode This is the normal operating mode for the FXTH87E. This mode is selected when the BKGD/PTA4 pin is high at the rising edge of reset. In this mode, the CPU executes code FXTH87ERM All information provided in this document is subject to legal disclaimers.

  • Page 12: Wait Mode

    FLASH program memory before the MCU is operated in RUN mode for the first time. When the FXTH87E is shipped from the NXP factory, the FLASH program memory is erased by default (unless specifically requested otherwise) so there is no program that could be executed in RUN mode until the FLASH memory is initially programmed.

  • Page 13: Stop Modes

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors 5.5 STOP Modes One of two stop modes are entered upon execution of a STOP instruction when the STOPE bit in the system option register is set. In all STOP modes, all internal clocks...

  • Page 14: Active Bdm Enabled In Stop Mode

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors Mode STOP1 STOP4 Sensor Measurement Interface (SMI) Optionally On Pressure P-cell Optionally On Optional Acceleration g-cell Optionally On Temperature Sensor (in ADC10) Optionally On Normal Temperature Restart Optionally On Optionally On...

  • Page 15: Mcu On-Chip Peripheral Modules In Stop Modes

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors 5.5.4 MCU on-chip peripheral modules in STOP modes When the MCU enters any STOP mode, system clocks to the internal peripheral modules except the wakeup timer and LFR detectors/decoder are stopped. Even in the exception case (ENDBM = 1), where clocks are kept alive to the BACKGROUND debug logic, clocks to the peripheral systems are halted to reduce power consumption.

  • Page 16: Lfr

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors 5.5.4.10 LFR When the LFR is enabled and the MCU enters STOP mode, the detectors in the LFR will remain powered up depending on the states of the bits selecting the periodic sampling.

  • Page 17: Memory

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors Memory The overall memory map of the FXTH87E resides on the MCU. 6.1 MCU memory map As shown in Figure 8, MCU on-chip memory in the FXTH87E consists of parameter registers, RAM, FLASH program memory for nonvolatile data storage, and I/O and control/status registers.

  • Page 18: Reset And Interrupt Vectors

    Temp Restart, Illegal opcode or address 6.3 MCU register addresses and bit assignments The registers in the FXTH87E are divided into these four groups: • Direct-page registers are located in the first 80 locations in the memory map; these are accessible with efficient direct addressing mode instructions.
  • Page 19 FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors Direct page registers are located within the first 256 locations in the memory map, so they are accessible with efficient direct addressing mode instructions, which requires only the lower byte of the address. Bit manipulation instructions can be used to access any bit in any direct-page register.
  • Page 20 FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors Address Register Name Bit 7 Bit 0 $0020-27 LFR Registers LFR Registers, see Table 8 Table 9 $0028 ADSC1 COCO AIEN ADCO ADCH[4:0] $0029 ADSC2 ADACT ADTRG ACFE ADCFGT $002A...
  • Page 21 FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors Table 10. RFM register summary - RPAGE = 0 Address Register Name Bit 7 Bit 0 $0030 RFCR0 BPS[7:0] $0031 RFCR1 FRM[7:0] $0032 RFCR2 SEND RPAGE PWR[4:0] $0033 RFCR3 DATA IFPD...

  • Page 22: High Address Registers

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors Address Register Name Bit 7 Bit 0 $0033 RFCR3 DATA IFPD ISPC IFID FNUM[3:0] $0034 RFCR4 RFBT[7:0] $0035 RFCR5 BOOST LFSR[6:0] $0036 RFCR6 VCO_GAIN[1:0] RFFT[5:0] $0037 RFCR7 RFIF RFEF RFVF...

  • Page 23: Mcu Parameter Registers

    $008F is used by the firmware for interrupt flags. 6.6 MCU RAM The FXTH87E includes static RAM. The locations in RAM below $0100 can be accessed using the more efficient direct addressing mode, and any single bit in this area can be accessed with the bit-manipulation instructions (BCLR, BSET, BRCLR, and BRSET).

  • Page 24: Flash

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors When security is enabled, the RAM is considered a secure memory resource and is not accessible through BDM or through code executing from non-secure memory. See Section 6.8 "Security" for a detailed description of the security feature.

  • Page 25: Program And Erase Command Execution

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors Parameter Cycles of FCLK Time if FCLK = 200 kHz Page erase 4000 20 ms Mass erase 20,000 100 ms Excluding start/end overhead 6.7.3 Program and erase command execution The steps for executing any of the commands are listed below. The FCDIV register must be initialized and any error flags cleared before beginning command execution.
  • Page 26 FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors • The next burst program command has been queued before the current program operation has completed. • The next sequential address selects a byte on the same physical row as the current byte being programmed.

  • Page 27: Access Errors

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors Write to FCDIV (1) Note 1: Required only once after reset. FLASH BURST Start PROGRAM FLOW FACCERR? Clear error FCBEF? Write to FLASH, to buffer address, and data Write command ($25) to FCMD...

  • Page 28: Flash Block Protection

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors • Writing a second time to FCMD before launching the previous command (There is only one write to FCMD for every command.) • Writing to any FLASH control register other than FCMD after writing to a FLASH address •...

  • Page 29: Vector Redirection

    6.8 Security The FXTH87E includes circuitry to prevent unauthorized access to the contents of FLASH and RAM memory. When security is engaged, FLASH and RAM are considered secure resources. Direct-page registers, high-page registers, and the BACKGROUND DEBUG controller are considered unsecured resources.

  • Page 30: Flash Registers And Control Bits

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors 1. Writing 1 to KEYACC in the FCNFG register. This makes the FLASH module interpret writes to the backdoor comparison key locations (NVBACKKEY through NVBACKKEY +7) as values to be compared against the key rather than as the first step in a FLASH program or erase command.

  • Page 31: Flash Clock Divider Register (Fcdiv)

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors 6.9.1 FLASH clock divider register (FCDIV) Bit 7 of this register is a read-only status flag. Bits 6 through 0 can be read at any time but can be written only once. Before any erase or programming operations are possible, write to this register to set the frequency of the clock for the nonvolatile memory system within acceptable limits.

  • Page 32: Flash Options Register (Fopt And Nvopt)

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors PRDIV8 DIV5:DIV0 Program/Erase Timing Pulse FCLK (Binary) (Decimal) (5 μs Min, 6.7 μs Max) 150 kHz 150 kHz 6.7 μs 6.9.2 FLASH options register (FOPT and NVOPT) During reset, the contents of the nonvolatile location NVOPT are copied from FLASH into FOPT.

  • Page 33: Flash Configuration Register (Fcnfg)

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors 6.9.3 FLASH configuration register (FCNFG) Bits 7 through 5 can be read or written at any time. Bits 4 through 0 always read 0 and cannot be written. Table 20. FLASH configuration register (FCNFG) (address $1823)

  • Page 34: Flash Status Register (Fstat)

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors 6.9.5 FLASH status register (FSTAT) Bits 3, 1, and 0 always read 0 and writes have no meaning or effect. The remaining five bits are status bits that can be read at any time. Writes to these bits have special meanings that are discussed in the bit descriptions.

  • Page 35: Flash Command Register (Fcmd)

    Reset, interrupts and system configuration This section discusses basic reset and interrupt mechanisms and the various sources of reset and interrupts in the FXTH87E. Some interrupt sources from peripheral modules are discussed in greater detail within other sections of this product specification. This section gathers basic information about all reset and interrupt sources in one place for easy reference.

  • Page 36: Computer Operating Properly (Cop) Watchdog

    (CCR) is set to block maskable interrupts so the user program has a chance to initialize the stack pointer (SP) and system control settings. The SP is forced to $00FF at reset. The FXTH87E has seven sources for reset: • Power-on reset (POR) •...

  • Page 37: Sim Test Register (Simtst)

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors COPT COP Overflow Time Clock COPCLKS Overflow Source (ms, nominal) Count (0.5 MHz) (1 MHz) (2 MHz) (4MHz) 0 Bus Clock 16.384 8.192 4.096 2.048 1 Bus Clock 32.768 16.384 8.192...

  • Page 38: Interrupts

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors Table 30. SIMTST register field descriptions Field Description Reserved Bit — These bits are reserved for factory trim and should not be altered by the user. reserved Temperature Restart High threshold — Binary coded from 0x00 to 0x07; recommend applications overwrite to 0x06 at each wakeup cycle.

  • Page 39: Interrupt Stack Frame

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors For compatibility with the M68HC08, the H register is not automatically saved and restored. It is good programming practice to push H onto the stack at the start of the interrupt service routine (ISR) and restore it just before the RTI that is used to return from the ISR.
  • Page 40 FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors stack the PCL, PCH, X, A, and CCR CPU registers, set the I bit, and then fetch the interrupt vector for the highest priority pending interrupt. Processing then continues in the interrupt service routine.

  • Page 41: Low-Voltage Detect (Lvd) System

    LVDV bit. After an LVD reset has occurred, the LVD system will hold the FXTH87E in reset until the supply voltage has risen above the level determined by LVDV bit. The threshold for falling and rising differ by a small amount of hysteresis. The LVD bit in the SRS register is set following either an LVD reset or POR.

  • Page 42: Lvd Interrupt Operation

    7.7 System clock control Several clock rate selections are possible with the FXTH87E using the BUSCLKS[1:0] control bits to select the clock frequency division of the HFO as given in Table 32.
  • Page 43 FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors from all low power modes. The LFO is always active and cannot be powered off by any software control. The control bits for the RTI are shown in Table Note: Regarding wake-up from Stop1, the reset vector is accessed, taking precedence over the interrupt vector.

  • Page 44: Temperature Sensor And Restart System

    (Dependent on 1-kHz LFO) 7.10 Temperature sensor and restart system The FXTH87E has two temperature sensing mechanisms. The first is an accurate sensor which is accessible through the ADC10 channel 1. The second is a less accurate, very low power sensor which generates a wakeup from STOP1 when the temperature crosses its threshold of detection.
  • Page 45 FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors Any Other Reset = Reserved Any of these reset sources that are active at the time of reset will cause the corresponding bit(s) to be set; bits corresponding to sources that are not active at the time of reset will be cleared.

  • Page 46: System Options Register 1 (Simopt1)

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors 7.11.2 System Options Register 1 (SIMOPT1) The following clock source and frequency selections are available using the system option register 1 as shown in Table Table 39. System option register 1 (SIMOPT1) (address $1802)

  • Page 47: System Operation Register 2 (Simopt2)

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors 7.11.3 System Operation Register 2 (SIMOPT2) The following clock source and frequency selections are available using the system option register 2 as shown in Table Table 41. System option register 2 (SIMOPT2) (address $1803)

  • Page 48: System Power Management Status And Control 2 Register (Spmsc2)

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors This bit can be written only one time after reset. Additional writes are ignored. Table 44. SPMSC1 register field descriptions Field Description Low-Voltage Detect Flag — Provided LVDE = 1, this read-only status bit indicates a low-voltage detect event.

  • Page 49: System Power Management Status And Control 3 Register (Spmsc3)

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors Table 46. SPMSC2 register field descriptions Field Description Reserved Bits — These bits are reserved should not be altered by the user. Any read returns a logical zero. Reserved Power Down Flag — This read-only status bit indicates the MCU has recovered from STOP1 mode.

  • Page 50: Free-Running Counter (Frc)

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors Field Description Low-Voltage Warning Voltage Select — The LVWV bit selects the LVW trip point voltage (V 0 Low-trip point selected (V LVDL LVWV 1 High-trip point selected (V LVDH Reserved Bits — These bits are reserved should not be altered by the user. Any read returns a logical zero.

  • Page 51: Software Handler Requirements

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors FRC_TIMER[7:0] Reset = Reserved 7.11.7.1 Software handler requirements Application developers should adhere to the following steps when entering and exiting software handler for the FRC: 1. Disable all interrupt sources 2.

  • Page 52: General Purpose I/O

    General Purpose I/O This section explains software controls related to general purpose input/output (I/O) and pin control. The FXTH87E has seven general-purpose I/O pins which are comprised of a general use 5-bit port A and a 2-bit port B. PTA[4:0] pins are shared with on-chip peripheral functions. PTB[1:0] pins are GPIO only...
  • Page 53 FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors PTxDDn Output enable PTxDn Output data Port read data SYNCHRONIZER Input data BUSCLKS aaa-028001 Figure 13. General purpose I/O block diagram   KBEDEy PTA[3:0] only KBIPEy PTxPEn PTxDDn Write PTxDn Port pin...

  • Page 54: Unused Pin Configuration

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors PTBPE[1:0] PTBDD[1:0] KBIPE[3:0] KBEDG[3:0] Pullup Pulldown (pull enable) (data direction) (KBI pin enable) (KBI Edge Select) disabled enabled disabled The data direction control bit (PTxDDn) determines whether the output buffer for the associated pin is enabled, and also controls the source for port data register reads.

  • Page 55: Pin Behavior In Stop Modes

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors 8.2 Pin behavior in STOP modes Pin behavior following execution of a STOP instruction depends on the STOP mode that is entered. An explanation of pin behavior for the various STOP modes follows: •...

  • Page 56: Port B Registers

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors = Reserved Table 58. Port A register pullup enable field descriptions Field Description Internal Pullup Enable for Port A Bit n — Each of these control bits determines if the internal pullup device is enabled for the associated PTA pin.
  • Page 57 FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors Table 62. Port B data register field descriptions Field Description Port B Data Register Bit n — For port B pins that are inputs, reads return the logic level on the pin. For port B pins that are configured as outputs, reads return the last value written to this register.

  • Page 58: Keyboard Interrupt

    NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors Keyboard Interrupt The FXTH87E has a KBI module with general purpose I/O pins. 9.1 Features The KBI features include: • Up to four keyboard interrupt pins with individual pin enable bits.

  • Page 59: External Signal Description

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors KBACK BUSCLK RESET SYNCHRONIZER KBIPE0 STOP BYPASS STOP KBEDG0 KBIPEn KBMOD KBEDGn aaa-028003 Figure 15. KBI block diagram 9.4 External signal description The KBI input pins can be used to detect either falling edges, or both falling edge and low level interrupt requests.

  • Page 60: Kbi Pin Enable Register (Kbipe)

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors Table 69.  KBISC register field descriptions Field Description Unused register bits, always read 0. Keyboard Interrupt Flag — KBF indicates when a keyboard interrupt is detected. Writes have no effect on KBF.

  • Page 61: Functional Description

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors = Reserved Table 73.  KBIES register field descriptions Field Description Keyboard Edge Selects — Each of the KBEDGn bits selects the falling edge/low level or rising edge/high level function of the corresponding pin).

  • Page 62: Kbi Initialization

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors register is used to select whether the resistor is a pullup (KBEDG[3:0] = 0) or a pulldown (KBEDG[3:0] = 1). 9.6.4 KBI initialization When a keyboard interrupt pin is first enabled it is possible to get a false keyboard interrupt flag.

  • Page 63: Programmer's Model And Cpu Registers

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors • Overflow, half-carry, negative, zero, and carry condition codes support conditional branching on the results of signed, unsigned, and binary-coded decimal (BCD) operations • Efficient bit manipulation instructions • Fast 8-bit by 8-bit multiply and 16-bit by 8-bit divide instructions •...

  • Page 64: Stack Pointer (Sp)

    1. The following paragraphs describe the functions of the condition code bits in general terms. For a more detailed explanation of how each instruction sets the CCR bits, refer to the HCS08 Family Reference Manual, volume 1, NXP Semiconductors document order number HCS08RMv1.
  • Page 65 FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors condition code register Carry Zero Negative Interrupt mask Half-carry (from bit 3) Two's complement overflow aaa-028005 Figure 17. Condition code register Table 74. CCR register field descriptions Field Description Two’s Complement Overflow Flag — The CPU sets the overflow flag when a two’s complement overflow occurs.

  • Page 66: Addressing Modes

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors Field Description Carry/Borrow Flag — The CPU sets the carry/borrow flag when an addition operation produces a carry out of bit 7 of the accumulator or when a subtraction operation requires a borrow. Some instructions — such as bit test and branch, shift, and rotate —...

  • Page 67: Extended Addressing Mode (Ext)

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors located. This is faster and more memory efficient than specifying a complete 16-bit address for the operand. 10.4.5 Extended addressing mode (EXT) In extended addressing mode, the full 16-bit address of the operand is located in the next two bytes of program memory after the opcode (high byte first).

  • Page 68: Special Operations

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors 10.5 Special operations The CPU performs a few special operations that are similar to instructions but do not have opcodes like other CPU instructions. In addition, a few instructions such as STOP and WAIT directly affect other MCU circuitry.

  • Page 69: Wait Mode Operation

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors The software interrupt (SWI) instruction is like a hardware interrupt except that it is not masked by the global I bit in the CCR and it is associated with an instruction opcode within the program so it is not asynchronous to program execution.

  • Page 70: Hcs08 Instruction Set Summary

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors 10.6 HCS08 instruction set summary 10.6.1 Instruction set summary nomenclature The nomenclature listed here is used in the instruction descriptions in Table 10.6.2 Operators ( ) = Contents of register or memory location shown inside parentheses ←...

  • Page 71: Ccr Activity Notation

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors Z = Zero indicator, bit 1 C = Carry/borrow, bit 0 (carry out of bit 7) 10.6.6 CCR activity notation – = Bit not affected 0 = Bit forced to 0 1 = Bit forced to 1 Þ...

  • Page 72: Address Modes

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors instruction. The assembler will calculate the 8-bit signed offset and include it in the object code for this instruction. 10.6.9 Address modes INH = Inherent (no operands) IMM = 8-bit or 16-bit immediate...
  • Page 73 FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors Effect Address on CCR Source Form Operation Description Opcode Operand Cycles Mode V H I N Z C Add Immediate H:X ← (H:X) + (M) Value (Signed) AIX #opr8i – – – – – – IMM...
  • Page 74 FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors Effect Address on CCR Source Form Operation Description Opcode Operand Cycles Mode V H I N Z C Waits For and Enter ACTIVE Processes BDM BGND BACK-GROUND Commands Until – – – – – – INH...
  • Page 75 FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors Effect Address on CCR Source Form Operation Description Opcode Operand Cycles Mode V H I N Z C Branch if Not 26 rr BNE rel Branch if (Z) = 0 –...
  • Page 76 FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors Effect Address on CCR Source Form Operation Description Opcode Operand Cycles Mode V H I N Z C Clear Carry Bit C ← 0 – – – – – 0 INH Clear Interrupt I ←...
  • Page 77 FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors Effect Address on CCR Source Form Operation Description Opcode Operand Cycles Mode V H I N Z C Decimal Adjust Accumulator After U – – Þ Þ Þ INH ADD or ADC of...
  • Page 78 FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors Effect Address on CCR Source Form Operation Description Opcode Operand Cycles Mode V H I N Z C PC ← (PC) + n (n = 1, 2, or 3) hh ll JSR opr8a Push (PCL);...
  • Page 79 FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors Effect Address on CCR Source Form Operation Description Opcode Operand Cycles Mode V H I N Z C ← dd dd destination MOV opr8a,opr8a DIR/DIR source MOV opr8a,X+ DIR/IX+ H:X ← (H:X) +...
  • Page 80 FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors Effect Address on CCR Source Form Operation Description Opcode Operand Cycles Mode V H I N Z C Pull X (Index SP ← (SP + PULX Register Low) – – – – – – INH 0x0001);...
  • Page 81 FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors Effect Address on CCR Source Form Operation Description Opcode Operand Cycles Mode V H I N Z C STA opr8a STA opr16a hh ll STA oprx16,X ee ff Store STA oprx8,X Accumulator in M ←...
  • Page 82 FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors Effect Address on CCR Source Form Operation Description Opcode Operand Cycles Mode V H I N Z C Transfer Accumulator to CCR ← (A) Þ Þ Þ Þ Þ Þ INH...
  • Page 83 FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors Bit-Manipulation Branch Read-Modify-Write Control Register/Memory 05  5 15  5 25  3 35  4 45  3 55  4 65  3 75  5 85  1 95  2 A5  2 B5  3 C5  4 D5  4 E5  3 F5  3 BRCLR2 BCLR2 STHX LDHX LDHX CPHX CPHX 3   2  ...

  • Page 84: Timer Pulse-Width Module

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors Bit-Manipulation Branch Read-Modify-Write Control Register/Memory 9E61 6 9ED1 5 9EE1 4 CBEQ 4 SP1 4 SP2 3 SP1 9ED2 5 9EE2 4 4 SP2 3 SP1 9E63 6 9ED3 5 9EE3 4 9EF3 6 CPHX 3 SP1 4 SP2 3 SP1 3 SP1 9E64 6 9ED4 5 9EE4 4 3 SP1 4 SP2 3 SP1...

  • Page 85: Features

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors the features and functions of the TPM1 are as described in the MC9S08RC16 product specification. The user has the option to connect the two timer channels to the PTA[3:2] pins, if those pins are not needed for an LFR channel or other general purpose I/O function.

  • Page 86: External Signal Description

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors BUSCLK CLOCK SOURCE PRESCALE AND SELECT SELECT DIVIDE BY OFF, BUS, XCLK, EXT 1, 2, 4, 8, 16, 32, 64, or 128 SYNC MAIN 16-BIT COUNTER INTERRUPT COUNTER RESET LOGIC...

  • Page 87: Register Definition

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors 11.4 Register definition The TPM1 includes: • An 8-bit status and control register (TPMSC) • A 16-bit counter (TPMCNTH:TPMCNTL) • A 16-bit modulo register (TPMMODH:TPMMODL) Each timer channel has: • An 8-bit status and control register (TPMCnSC) •...

  • Page 88: Timer Counter Registers (Tpm1Cnth:tpm1Cntl)

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors Field Description Clock Source Select — As shown in Table 78, this 2-bit field is used to disable the TPM1 system or select one of three clock sources to drive the counter prescaler. The internal DX source is synchronized to the bus CLKS[B:A] clock by an on-chip synchronization circuit.

  • Page 89: Tab. 84. Timer Counter Modulo Register High (Tpm1Modh) (Address $0013)

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors BACKGROUND mode became active even if one or both bytes of the counter are read while BACKGROUND mode is active. 11.4.3 Timer counter modulo registers (TPM1MODH:TPM1MODL) The read/write TPM1 modulo registers contain the modulo value for the TPM1 counter.

  • Page 90: Tab. 87. Tpm1C0Sc Register Field Descriptions

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors Table 87.  TPM1C0SC register field descriptions Field Description Channel 0 Flag — When channel n is configured for input capture, this flag bit is set when an active edge occurs on the channel n pin. When channel 0 is an output compare or edge-aligned PWM channel, CH0F is set when the value in the TPM1 counter registers matches the value in the TPM1 channel 0 value registers.

  • Page 91: Tab. 89. Timer Channel 0 Value Register High (Tpm1C0Vh) (Address $0016)

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors If the associated port pin is not stable for at least two bus clock cycles before changing to input capture mode, it is possible to get an unexpected indication of an edge trigger.

  • Page 92: Tab. 92. Tpm1C1Sc Register Field Descriptions

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors = Reserved Table 92.  TPM1C1SC register field descriptions Field Description Channel 1 Flag — When channel n is configured for input capture, this flag bit is set when an active edge occurs on the channel n pin.

  • Page 93: Tab. 94. Timer Channel 1 Value Register High (Tpm1C1Vh) (Address $0019)

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors CPWMS MS1B:MS1A ELS1B:ELS1A Mode Configuration High-true pulses (clear output on compare) Edge-aligned low-true pulses (set output on compare) High-true pulses (clear output on compare-up) Center-aligned low-true pulses (set output on compare-up) If the associated port pin is not stable for at least two bus clock cycles before changing to input capture mode, it is possible to get an unexpected indication of an edge trigger.

  • Page 94: Counter

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors the main 16-bit counter in the TPM1. Each TPM1 channel is optionally associated with an MCU pin and a maskable interrupt function. The TPM1 has center-aligned PWM capabilities controlled by the CPWMS control bit in TPM1SC.

  • Page 95: Channel Mode Selection

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors changes direction at the transition from the value set in the modulus register and the next lower count value. This corresponds to the end of a PWM period. (The 0x0000 count value corresponds to the center of a period.)

  • Page 96: Center-Aligned Pwm Mode

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors for input capture or output compare functions. The period of this PWM signal is determined by the setting in the modulus register (TPM1MODH:TPM1MODL). The duty cycle is determined by the setting in the timer channel value register (TPM1CnVH:TPM1CnVL).

  • Page 97: Tpm1 Interrupts

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors not necessary). This is not a significant limitation because the resulting period is much longer than required for normal applications. TPM1MODH:TPM1MODL = 0x0000 is a special case that should not be used with center-aligned PWM mode.

  • Page 98: Clearing Timer Interrupt Flags

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors output compare or PWM modes, the interrupt flag is set each time the main timer counter matches the value in the 16-bit channel value register. See Section 7 "Reset, interrupts and system configuration"...

  • Page 99: Tab. 96. Adc10 Channel Assignments

    RF data. The resulting interactions will degrade the accuracy of the measurements. The FXTH87E measures six physical parameters for use in the tire pressure monitoring application: pressure, temperature, battery voltage, two external voltages and an optional X- and/or Z-axis acceleration.

  • Page 100: Pressure Measurement

    The transfer equation of the 100-900 kPa range is: The transfer equation of the 100-1500 kPa range is: Due to calibration routines and parameters stored in the FXTH87E, the pressure range is selected at production and cannot be changed in the field.

  • Page 101: Internal Band Gap

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors 12.3.1 Internal band gap An internal band gap voltage reference is provided to take measurements of the supply voltage. The resulting transfer equation: 12.3.2 External voltages Measurements of an external voltage on either the PTA0 or PTA1 pins can be made and referenced to the internal band gap voltage.

  • Page 102: Optional Battery Condition Check

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors 12.5 Optional battery condition check The condition of the battery can be periodically checked to determine the battery’s internal impedance, R , which is a function of both temperature and the remaining BATT battery capacity.

  • Page 103: Measurement Firmware

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors It is recommended that this calculation be performed with a reasonable current load on the battery of approximately 3 mA (R approximately 1000 ohms). LOAD 12.6 Measurement firmware The firmware for making measurements is comprised of two function calls as described Section 16 "Firmware".

  • Page 104: Thermal Shutdown

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors COMP Comp COMP_VOLTAGE VOLT Voltage Input Raw Voltage READ_VOLTAGE Voltage VOLT COMP Comp COMP_TEMPERATURE TEMP Temperature Input Raw Temperature READ_TEMPERATURE Temperature TEMP COMP Comp COMP_PRESSURE PRESS Pressure Input Raw Pressure...

  • Page 105: Temperature Shutdown Recovery

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors programmed high temperature is reached the MCU will turn off all operating functions and enter the STOP1 mode. 12.7.3 Temperature shutdown recovery The MCU can be restarted by the Temperature Restart (TR) module when the temperature returns within the normal temperature range, T .

  • Page 106: Free-Running Counter (Frc)

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors Reset Firmware Firmware initialization configuration of after a reset device TRE bit cleared and TR trim bits enabled to be written Read temperature using Load TR trim TPMS_COMP_TEMPERATURE bits from...

  • Page 107: Periodic Wakeup Timer

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors bytes into a buffer where they remain until a second byte is read ($1808 or $1809). This allows coherent 16-bit reads in either order. The coherency mechanism is automatically restarted by an MCU reset, exit of STOP1, or a write to the PMCT register at address $180B bits 7 = 1, or bit 5 = 0.

  • Page 108: Tab. 97. Pwu Divider Register (Pwudiv) (Address $0038)

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors reached and are then reset to zero. Reading the status of either of these counters will return a zero content if done immediately after the interrupt or reset is generated.

  • Page 109: Tab. 99. Pwu Control/Status Register 0 (Pwucs0) (Address $0039)

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors period of the resulting interrupt also generates the clock, RCLK, for the periodic reset timing. Table 99. PWU Control/Status register 0 (PWUCS0) (address $0039) WUT[5:0] WUFAK Reset — Table 100. PWUSC0 register field descriptions...

  • Page 110: Tab. 102. Pwu Control/Status Register 1 (Pwucs1) (Address $003A)

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors 13.4 PWU control/status register 1 — PWUCS1 The PWUSC1 register contains six bits to select the division of the incoming RCLK clock period and provide interrupt flag and acknowledge bits as described in Table 102.

  • Page 111: Tab. 105. Pwus Register Field Descriptions

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors = Reserved Table 105. PWUS register field descriptions Field Description Page Selection — The PSEL read/write bit selects whether the other bits are read from the WUT or PRST counters. This bit is cleared by a power on reset that is not created by an exit from the STOP mode, but is unaffected by other resets.

  • Page 112: Active Bdm/Foreground Commands

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors If the module generates a periodic reset the module will cause the MCU to exit the power saving mode as a POR. The PRF flag will be set to indicate periodic reset; write 1 to PRFACK to clear this flag.

  • Page 113: Features

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors DATA SLICER SUMMATOR AVERAGE FILTER CLAMP RECTIFIER0 RECTIFIER1 RECTIFIER2 RECTIFIER3 AMP1 BUFF1 AMP2 BUFF2 AMP3 BUFF3 SENSITIVITY Vref_sensitivity CARRIER LOGIC BLOCK 1 DETECTOR 129 kHz LOGIC BLOCK 2 · ON/OFF CYCLING ·...

  • Page 114: Modes Of Operation

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors • Optional continuous monitoring and decode of the LF detector. • Selectable MCU interrupt when a received data byte is ready in an LFR buffer, when a Manchester error is detected in the frame, when an ID is received or when a valid carrier has been detected.

  • Page 115: Lfr Data Mode States

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors to enable the LF input depending on the application requirements. The SENS[1:0] bits in the LFCTL1 register allows the user to select one of two input sensitivity thresholds which determines the signal level required before the input carrier will be detected. The sensitivity setting is used during carrier detection but does not affect reception after the carrier has been detected.
  • Page 116 FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors a TPMS frame, a timeout will turn off the LFR module. This timeout can be program through TIMOUT bit the LFCTL4 register. LFEN = 0 or SRES Disabled (at any state)

  • Page 117: Auto-Zero Sequence

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors 14.7 Auto-zero sequence An auto-zero sequence is performed periodically on the input amplifier to cancel offset errors. During reception of the SYNC pattern and body of the message, auto-zero operations are synchronized to data edges of the incoming signal to avoid interfering with normal reception.

  • Page 118: Manchester Decode

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors 14.10 Manchester decode When the LFPOL bit is clear, a logic one bit is defined as no LF carrier present for the first half of the bit time; and a logic zero bit is defined as LF carrier present for the first...

  • Page 119: Input Signal Envelope

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors Regarding the SYNC pattern which is non-Manchester coded, the duty cycle is applied on all falling edges with the same proportion as a 1T Manchester symbol, as shown in Figure aaa-028024 Figure 31. Impact of duty-cycle on SYNC pattern...

  • Page 120: Telegram Verification

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors 14.13 Telegram verification The LFR has control bits to allow flexibility in the telegram format and protocol to allow the LFR to adapt to a variety of systems. The LFR can operate in a normal data receive mode where it receives complete telegrams, or in a carrier detect mode where it only checks for a carrier.

  • Page 121: Error Detection And Handling

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors the LFR considers the message complete and terminates the LFR operation without setting the data ready flag (LFDRF). If data follows the ID, it is serially received and when 8 bits have been received the LFR copies this byte into the LFDATA register and sets the LFDRF flag.

  • Page 122: Tab. 106. Lfr Control Register 1 (Lfctl1) (Address $0020)

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors to ensure operation within specified limits. After these trim values are written, they remain constant until the next MCU reset. The application program must set up control bits and registers to configure the LFR to determine the structure of the message telegram, the input sensitivity, and other LFR options.

  • Page 123: Tab. 108. Lfr Control Register 2 (Lfctl2) (Address $0021)

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors Field Description Wakeup ID Selection — Selects the existence and length of the wakeup ID. Reset clears these bits. 00 No ID expected 01 8-bit ID based on the contents of the LFIDL register IDSEL[1:0] 10 16-bit ID based on the contents of the LFIDH and LFIDL registers...

  • Page 124: Tab. 110. Lfr Control Register 3 (Lfctl3) (Address ($0022)

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors Field Description LF Sampling ON Time Select — These read/write control bits select the length of time that the LFR input detector is turned on at the beginning of each sampling interval set by the LFSTM bits. This ON time is...

  • Page 125: Tab. 111. Lfctl3 Register Field Descriptions

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors Table 111. LFCTL3 register field descriptions Field Description LF Detector Output — This read-only bit follows the bit slicer output signal that goes high during the presence of a carrier. It may change at any time. This bit is read only and unaffected by any reset.

  • Page 126: Tab. 112. Lfr Control Register 4 (Lfctl4) (Address $0023)

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors 14.17.4 LFR control register 4 (LFCTL4) LFCTL4 contains local interrupt enable control bits. The provided I-interrupts are not globally masked by the I bit in the CPU’s CCR, setting one or more of these interrupt enable control bits will cause a CPU interrupt to be requested whenever the flag bit associated with the corresponding LFR interrupt source becomes set.

  • Page 127: Tab. 114. Lfr Status Register (Lfs, Lpage = 0) (Address $0024)

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors Field Description SYNC Time Out Select — These two read/write bits select the period of time that the LFR will search for a SYNC pattern in the data mode. If the SYNC pattern is not detected the LFR will be turned off after this delay time.

  • Page 128: Tab. 116. Lfr Data Register (Lfdata) When Lpage = 0 (Address $0025)

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors Field Description LF Receive Data Overflow Flag — In data receive mode, this read-only status flag is set when a complete byte of data has been received and written into the LFDATA register, but the previously received byte was not read from LFDATA register yet.

  • Page 129: Tab. 117. Lfdata Register Field Descriptions

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors Table 117. LFDATA register field descriptions Field Description Receive Data [7:0] — This is the received data from the LFR when in the data mode. All bits are read-only and any writes to these bits will be ignored. Reading this register will clear the LFDRF.

  • Page 130: Tab. 122. Lfctrle Register Field Description

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors Table 122. LFCTRLE register field description Field Description Reserved bits — Not for user access. Reserved LOGAMP AZ Sequencer Control — Control bits for AZ and trim within the LOGAMP. X00 Nominal AZ sequence — recommended setting...

  • Page 131: Tab. 126. Lfctrlc Register Field Descriptions

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors Field Description ON Behavior Mode — This read/write bit selects how an error will affect the ON time. This bit is cleared by reset. 0 Any error will stop the ON time.

  • Page 132: Tab. 128. Lfctrlb Register Field Descriptions

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors Field Description DeQing System enable — The bit controls the DeQing system. 0 DeQing disabled. DEQEN 1 DeQing enabled. 14.17.10 LFR control register B (LFCTRLB, LPAGE = 1) The LFCTRLB register contains control bits for the LF detector and decoder. It is only accessible when the LPAGE bit is set.

  • Page 133: Tab. 130. Lfctrla Register Field Descriptions

    LF signals. The resulting interactions will degrade the performance of the RF output spectrum. The FXTH87E consists of an RF module (RFM) with external crystal-driven oscillator, VCO, fractal-n PLL and RF output amplifier (PA) for an antenna. It also contains a small state machine controller, random time generator and hardware data buffer for automated output or direct control from the MCU.

  • Page 134: Rf Data Modes

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors 256-BIT DATA BUFFER RINT LFSR MODULATION STATE RANDOM CONTROL MACHINE CONTROL REGISTERS AND LOGIC 500 kHz FRACTIONAL-N DIVIDER CRYSTAL PHASE LOW-PASS OSCILLATOR DETECTOR FILTER VOLT AVDD AVDD AVSS aaa-028030 VREG Figure 37. RF transmitter block diagram...

  • Page 135: Mcu Direct Mode

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors modulation. Therefore, the tolerance on the data rate will depend on the characteristics of the external crystal. Once the data buffer is emptied the data transfer stops; the RF output stage is turned off;...

  • Page 136: Data Buffer Length

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors Maximum RFB0 RFB1 RFB2 RFB3 RFB4 RFB5 RFBA RFBB RFBC RFBD RFBE RFBF 258-bit format 80-bit format RFB0 RFB1 RFB2 RFB3 RFB4 RFB5 RFB6 RFB7 RFB8 RFB9 optional EOM 53-bit format...

  • Page 137: Initial Time Interval

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors time not to scale 1 to 16 data frames with identical data SPACE DATA FRAME SPACE DATA FRAME SPACE DATA FRAME Initial interval Interframe intervals Start of time interval for...

  • Page 138: Interframe Time Intervals

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors 15.3.2 Interframe time intervals When generating an interframe time interval the MCU loads the RFM interval generator variables and then goes to the STOP1 mode. When the interframe time interval ends the data in the RFM data buffer is automatically sent and the MCU will wake at the end of the transmission.

  • Page 139: Tab. 131. Randomization Interval Times

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors 7-bit random number RFMRST Galois primitive polynomial = X7 + X3 + 1 aaa-028034 Figure 41. LFSR implementation A value of all zeros in the LFSR will remain unchanged with every clock input and cannot be used as a starting "seed."...

  • Page 140: Rfm In Stop1 Mode

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors Nominal frame number Frame Value of Number time interval added (ms) interval where FNUM[3:0] of frames time added Minimum Maximum 3 - 4 4 - 5 5 - 6 6 - 7...

  • Page 141: Nrz Encoding

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors time. The polarity of this transition is selected by the POL bit. Unlike Manchester coding there is always a signal transition at the boundaries of each bit time. When the POL bit...
  • Page 142 FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors high FSK = f OOK = f FSK = f OOK = OFF bit time bit time Consecutive “0 data bits Consecutive “1 data bits “001101 data bits aaa-028036 Figure 43. Manchester data bit encoding (POL = 1)  ...

  • Page 143: Rf Output Stage

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors high high FSK = f OOK = f FSK = f OOK = OFF bit time bit time bit time bit time Consecutive “0 data bits Consecutive “1 data bits “001101...

  • Page 144: Transmission Error

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors 15.6.4 Transmission error Any transmission will be aborted if one of the following occurs: 1. The RCTS signal does not become active within the t time. LOCK 2. The PLL falls out of lock after once being set and the SEND bit is still active.

  • Page 145: Tab. 133. Rfm Control Register 0 (Rfcr0) (Address $0030)

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors 15.9 RFM registers The RFM contains twelve registers to control its functions and 32 registers to provide access to the output data buffer. 15.9.1 RFM Control Register 0 — RFCR0...

  • Page 146: Tab. 136. Rfm Control Register 1 (Rfcr1) (Address $0031)

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors Table 136. RFM control register 1 (RFCR1) (address $0031) FRM[7:0] Reset Table 137. RFCR1 field descriptions Field Description Frame Bit Length — The FRM[7:0] control bits select the number of bits in each datagram. The number of bits is determined by the binary value of the FRM[7:0] bits plus one.

  • Page 147: Power Working Domains

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors Field Description RF Amplifier Power Level — The PWR[4:0] control bits select the optimum power output of the RF power amplifier. These power output levels assume optimal matching network to the RF pin. The PWR[4:0] control bits are cleared a RFM reset.

  • Page 148: Tab. 140. Rfm Control Register 3 (Rfcr3) (Address $0033)

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors • T = 0 °C to 25 °C and V = 2.5 V to 3.6 V • T = 60 °C to 125 °C and V = 2.5 V to 3.6 V Typical consumption VDD = 3.6 V...

  • Page 149: Tab. 142. Rfcr4 Register - Base Time Variable (Address $0034)

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors Field Description Interframe Interrupt Delay — The IFID control bit selects when the RFIF bit is set and the MCU is interrupted. The IFID control bit is cleared by the RFMRST signal.

  • Page 150: Tab. 145. Rfcr5 Field Descriptions

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors Table 145. RFCR5 field descriptions Field Description BOOST — This bit controls the VCO power consumption in order to decrease the phase noise required by the Japanese regulation. The BOOST control bit is cleared by the RFMRST signal.

  • Page 151: Tab. 149. Rfcr7 Field Descriptions

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors RFIAK RFMRST Reset = Reserved Table 149. RFCR7 field descriptions Field Description RF Interrupt Flag— The read-only RFIF status bit indicates if the RF transmission has ended properly when using the data buffer mode and the SEND bit has been cleared. Writes to this bit will be ignored. The RFIF status bit is cleared by writing a logical one to the RFIAK bit or the RFMRST bit.

  • Page 152: Tab. 151. Pll Control Registers A (Pllcr[1:0], Rpage = 0) (Address ($0039)

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors 15.17 PLL control registers A - PLLCR[1:0], RPAGE = 0 The PLLCR[1:0] registers contain 16 control bits for the RFM as described in Table 150 Table 151. These bits are only accessible when the RPAGE bit is cleared.

  • Page 153: Tab. 154. Pll Control Registers B (Pllcr[3:2], Rpage = 0) (Address $003B)

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors 15.18 PLL control registers B - PLLCR[3:2], RPAGE = 0 The PLLCR[3:2] registers contain 16 control bits for the RFM as described in Table 153 Table 154. These bits are only accessible when the RPAGE bit is cleared.

  • Page 154: Tab. 156. Rfm Epr Registers (Epr, Rpage = 1, Vcd_En = 0) (Address $0038)

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors 15.19 EPR register — EPR (RPAGE = 1) The EPR register contains eight control bits for the RFM as described in Table 156. The function of the upper 4 bits depends on the state of the VCD_EN bit.

  • Page 155: Tab. 159. Rf Data Registers (Rfd[31:0])

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors divided into two pages of 128 bits as selected by the RPAGE bit in the RFCR2. These as described in Table 159. These bits are unaffected by any reset. The data buffer is unloaded to the RF output starting with the least significant bit (RFD0) in the least significant byte (RFB0) up through the most significant bit (RFD255) in the most significant byte (RFB31).

  • Page 156: Firmware

    16.2 Function documentation The following subsections describe the details of the firmware routines. Further details can be found in the latest version of the FXTH87E Embedded Firmware User Guide. FXTH87ERM All information provided in this document is subject to legal disclaimers.

  • Page 157: Tab. 161. Fxth87Ex02 Single Z-Axis Firmware Summary And Jump Routines

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors 16.2.1 General rules 1. No output parameter can use the extreme codes (all zero’s or all one’s). 2. The all zero’s output code will always indicate a fault and the status byte will indicate the source of the error.

  • Page 158: Fxth87E Dual Xz-Axis Firmware Routines

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors Address Routine Description E03C Reserved Reserved E03F TPMS_RF_SET_TX Initiate RF transmission E042 TPMS_RF_DYNAMIC_POWER Adjusts PA for uniform power output E045 TPMS_MSG_INIT Initialization of the emulated serial communication E048 TPMS_MSG_READ Reading data from emulated serial interface...

  • Page 159: Tab. 162. Fxth87Ex1X Dual Xz-Axis Firmware Summary And Jump Routines

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors The firmware table is comprised of 3-byte entries where the first byte is the operational code for the JMP instruction, and the following two bytes are the absolute address pointing to the location of the firmware function.

  • Page 160: Tab. 163. Device Id Coding Summary

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors Address Routine Description E05D TPMS_MSG_READ Reading data from emulated serial interface E060 TPMS_MSG_WRITE Writing data on emulated serial interface E063 TPMS_CHECKSUM_XOR Calculates a checksum for given buffer in XOR E066...

  • Page 161: Definition Of Signal Ranges

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors ID27 — 0 to identify FXTH87E family ID28:29 — Upper 2 bits of assembly lot ID ID30 — 0x1 to identify sub-con B, 0x0 to identify sub-con A ID31 — 0x1 to identify NXP as device supplier Note: Prior to erasing the flash memory, users are advised to first copy the contents of the CODE0 through CODE5 data into a secure and retrievable database.
  • Page 162 FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors by the firmware to the application software as either the raw ADC10 result or further compensated and scaled for an output between one and the maximum digital value minus one. The minimum digital value of zero and the maximum digital value are reserved as error codes.

  • Page 163: Memory Resource Usage

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors 16.3 Memory resource usage The firmware uses the top 8192 bytes of the FLASH memory map. At address $FC00, 1024 bytes are protected from erasure, containing the sensitivity and offset coefficients for the transducers and clocks.

  • Page 164: Bkgd/Pta4 Pin Description

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors to trace one user instruction at a time, or GO to the user program from ACTIVE BACKGROUND mode. • Non-intrusive commands can be executed at any time even while the user’s program is running.

  • Page 165: Communication Details

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors When no debugger pod is connected to the 6-pin BDM interface connector, the internal pullup on BKGD/PTA4 chooses normal operating mode. When a debug pod is connected to BKGD/PTA4 it is possible to force the MCU into ACTIVE BACKGROUND mode after reset.
  • Page 166 FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors Figure 51 shows the host receiving a logic 1 from the target HCS08 MCU. Because the host is asynchronous to the target MCU, there is a 0-to-1 cycle delay from the host- generated falling edge on BKGD/PTA4 to the perceived start of the bit time in the target MCU.

  • Page 167: Bdc Commands

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors 17.2.3 BDC commands BDC commands are sent serially from a host computer to the BKGD/PTA4 pin of the target HCS08 MCU. All commands and data are sent MSB-first using a custom BDC communications protocol.
  • Page 168 FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors Active BDM/ Description Command Mnemonic Coding Structure Non-intrusive Re-read byte from address just read and report READ_LAST Non-intrusive E8/SS/RD status WRITE_BYTE Non-intrusive C0/AAAA/WD/d Write a byte to target memory WRITE_BYTE_WS...

  • Page 169: Bdc Hardware Breakpoint

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors • Drives BKGD/PTA4 high for a brief speedup pulse to get a fast rise time (This speedup pulse is typically one cycle of the fastest clock in the system.) • Removes all drive to the BKGD/PTA4 pin so it reverts to high impedance •...

  • Page 170: Bdc Status And Control Register (Bdcscr)

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors These registers are accessed with dedicated serial BDC commands and are not located in the memory space of the target MCU (so they do not have addresses and cannot be accessed by user programs).

  • Page 171: Bdc Breakpoint Match Register (Bdcbkpt)

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors Field Description Force/Tag Select — When FTS = 1, a breakpoint is requested whenever the CPU address bus matches the BDCBKPT match register. When FTS = 0, a match between the CPU address bus and the BDCBKPT register causes the fetched opcode to be tagged.

  • Page 172: Battery Charge Consumption Modeling

    BDFR reset. This bit cannot be written from a user program. 18 Battery charge consumption modeling The supply current consumed by the FXTH87E can be estimated using the following basic model. 18.1 Standby current The overall charge consumed by the standby features is:...

  • Page 173: Transmission Events

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors • n = Total number of voltage measurements over lifetime VOLT 18.3 Transmission events The overall charge consumed by the transmissions is: (15) where: • Q = Transmit charge over lifetime, t , in mA-hr •...

  • Page 174: Revision History

    • Performed minor corrections throughout the narrative to conform with NXP guidelines. • Section 1.3 "Related documentation": Revised the steps providing a direct link to the FXTH87E page on NXP.com. • Section 2.2 "Features and benefits": Added "Optional XZ- or" before the feature "Z-axis accelerometer with adjustable offset option".
  • Page 175 FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors Document ID Release date Description FXTH87ERM v.3.0 20180305 • Section 2.2 "Features and benefits": Revised bullet "Real-Time Interrupt driven by LFO with interrupt intervals of 8, 16, 32, 64, 128, 256, 512 or 1024 ms"...

  • Page 176: Legal Information

    NXP Semiconductors products in order to avoid a of use of such information. default of the applications and the products or of the application or use by customer’s third party customer(s).
  • Page 177 FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors Tables Tab. 1. Configuration options ........2 Tab. 45. System power management status and Tab. 2. Part number breakdown ........3 control 2 register (SPMSC2) (address Tab. 3. Part marking breakdown ........3 $180A) .............

  • Page 178: Table Of Contents

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors Tab. 84. Timer counter modulo register high Tab. 124. LFCTRLD register field descriptions ....130 (TPM1MODH) (address $0013) ...... 89 Tab. 125. LFR control register C (LFCTRLC, LPAGE = Tab. 85.
  • Page 179 FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors Tab. 164. Device ID coding descriptions ....... 161 Tab. 168. System background debug force reset Tab. 165. BDC command summary ......167 register (SBDFR) ...........172 Tab. 166. BDC status and control register (BDCSCR) ...170 Tab.
  • Page 180 FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors Contents About this document .......... 1 5.5.4.14 Temperature sensor ........16 Purpose ..............1 5.5.4.15 Temperature restart ......... 16 Audience ............1 5.5.5 RFM module in STOP modes ......16 Related documentation ........1 5.5.5.1...

  • Page 181: Tab. 86. Timer Channel 0 Status And Control Register

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors 7.11.5 System Power Management Status and 10.5.5 BGND instruction ..........69 Control 2 Register (SPMSC2) ......48 10.6 HCS08 instruction set summary ...... 70 7.11.6 System Power Management Status and 10.6.1...

  • Page 182: Tab. 123. Lfr Control Register D

    FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors 13.3 PWU control/status register 0 — PWUCS0 15.5.2 Bi-Phase encoding .........140 (address $0039) ..........108 15.5.3 NRZ encoding ..........141 13.4 PWU control/status register 1 — PWUCS1 ..110 15.6 RF output stage ..........143 13.5...
  • Page 183 FXTH87E NXP Semiconductors FXTH87E, Family of Tire Pressure Monitor Sensors 18.3 Transmission events ........173 18.4 Total consumption ......... 173 Revision history ..........174 Legal information ..........176 Please be aware that important notices concerning this document and the product(s) described herein, have been included in section 'Legal information'.