Figure 3-42. Xtl 1500 Controller Section - Motorola ASTRO XTL 1500 Detailed Service Manual

Theory of Operation: Controller Section
From ABACUS (U6000)
To TX Modulation DAC (U0900)
To ABACUS (U6000),
LV-FRAC-N (U6751),
DAC (U0959), ADC (U0953)
Keyfail
Volume POT
PGA's
U0201, U0202
Mic
The controller consists of digital logic comprised of a microprocessor (the Patriot IC, U100) and
memory consisting of a 512K x 16 SRAM (U103) and a 4M x 16 FLASH ROM (U102). The
microprocessor is a dual-core processor that contains a DSP56600 core and an MCORE
microcontroller with custom peripherals. The term, MCU, refers to the MCORE controller section of
the Patriot IC. The FLASH ROM contains the programs that the Patriot microprocessor executes and
is used to store customer-specific information and radio-personality features that, together,
constitute the codeplug. It allows the controller firmware to be reprogrammed for future software
upgrades or feature enhancements. The SRAM is used for scratchpad memory during program
execution.
The controller performs the programming of all peripheral ICs. This is done via a serial peripheral
interface (SPI) bus and through General-Purpose Input/Outputs (GPIO) from the Patriot IC. ICs
programmed through this interface include the LV Frac-N synthesizer, ABACUS III IC, D/A converter
(DAC), A/-D converter (ADC), and volume digital potentiometer.
In addition to the SPI bus, the controller also maintains two asynchronous serial busses: the SB9600
bus and an RS-232/USB serial bus. The SB9600 bus interfaces the controller section to different
hardware accessories, some of which may be external to the radio, including the control head. The
RS-232/USB bus is used as a common data interface for external devices and for programming/
flashing the radio.
User input is from the control head and is sent to the controller through the SB9600 bus. Feedback to
the user is provided by the control-head display.
The controller schedules the activities of the DSP, including setting operational modes and
parameters. The DSP section of the processor contains an 84K x 24 program RAM, 2K x 24 program
ROM, and 62K x 16 data RAM, which are all integrated into the Patriot IC. The vocoder subsystem
consists of this DSP core, the modulation DAC (U0900), and the voice CODEC (U0200).
6815854H01-A
PATRIOT
BBP RX 1.2MHz CLK: 20kHz FS
56600 DSP
BBP TX 2.4MHz CLK: 48kHz FS
SAP SSI Digital Audio
512kHz CLK, 8kHz FS
DSP RAM
SPI (CLK, MOSI, MISO)
MCORE
UART's
SB9600
(UART B)
AUDIO
CODEC
U0200
U0206 SB9600
VIP's
EMERG,
PTT*,
AUDIO PA
IGNITION
U0204
5V SWB+ A+
Speaker
Control Head

Figure 3-42. XTL 1500 Controller Section

1.55V
2.85V
SW_B+
16.8MHz
From RF Ref. Oscillator
32kHz
8MB
1.8V
FLASH
EIM
512kB
1.8V
SRAM
I/O,
USB/RS232
(UART A)
To Audio, PATRIOT,
Power Control, UART
RS232 USB
XCVR XCVR
U0305 U0304
Circuit
SWB+
RS232 (12V)
Speaker
SB9600 (5V)
Rear Accessory Connector
SW_A+
9V
Regulator
LM2941T
9.3V
To SB9600
5V
and VIP Circuitry
Regulator
MC78M05
5V
2.85V
1.8V 1.55V
Regulator
Regulator Regulator
LP2951 LP2951 LP2951
2.85V 1.8V 1.55V
To Memory To PATRIOT CORE
XCVRs, Secure
RS232 (4-wire)
USB
MAEPF-27893-O
June 15, 2005
3-63