Motorola ASTRO XTS 5000 Detailed Service Manual page 58

Theory of Operation
: VOCON Board
NOTE: Refer to
of VOCON schematics that will aid in the following discussion.
3.2.2.1 Patriot IC U401
The Patriot IC U401 is a dual-core processor that contains both a 32-bit microcontroller unit (MCU)
and a 16-bit digital signal processor (DSP) in one IC package. It comes in a 256-pin, ball-grid array
(BGA) package with 1mm pitch solder balls. On the NTN9564, NNTN4563, and NNTN4819 VOCON
boards, the dual-core processor is supplied with two voltages: 1.8 V (E401) and 3 V (E402). The
1.8 V supply is used as the core voltage, as well as the interface voltage, to the memory devices and
display (1.8 V display interface only for the NTN9564 VOCON board). Most of the pins on the Patriot
IC operate from the 3 V supply.
The NNTN4717 kit uses a new dual-core processor which requires some different operating
voltages. The 1.8 V supply is used as the interface to the memory devices, unchanged from the
original processor. A 1.55 V supply is used for the core voltage and the clock amplifier module. The
remaining pins of the processor use a 2.9 V supply.
NOTE: GPIO voltage for the NTN9564, NNTN4563, and NNTN4819 VOCON boards is 3.0 V.
NOTE: GPIO voltage for the NNTN4717 and NNTN5567 VOCON board is 2.9 V.
Two main clocks are provided to the Patriot IC. The CKIH pin (C452) is provided a 16.8 MHz sine
wave. This is the most important clock since it is internally used to generate the clocks for both the
MCU and DSP cores, as well as most of the peripherals. A 3 V peak-to-peak 32 kHz square wave
(32 kHz test point) is generated by the Flipper IC U301 and supplied to the CKIL pin on the Patriot
IC. While not as widely used as the 16.8 MHz clock, the 32 kHz clock is needed by some
components in the Patriot including the reset circuitry.
3.2.2.1.1 Microcontroller Unit (MCU)
The MCU portion of the Patriot IC has 22.5k x 32 bits of internal RAM and 1k x 32 bits of internal
ROM, which is used for the bootstrapping code. The MCU has several peripherals including an
External Interface Module (EIM), the Multiple Queue Serial Peripheral Interface (MQSPI), two
Universal Asynchronous Receiver/Transmitter (UART) modules, and the One-Wire Interface
module. The MCU communicates internally to the DSP through the MCU/DSP Interface (MDI).
External Interface Module (EIM)
The External Interface Module (EIM) is the MCU interface to the SRAM U403 and Flash Memory
U402, as well as the display (only for the NTN9564 VOCON kit). The EIM lines include 24 external
address lines, 16 external bi-directional data lines, 6 chip selects lines, read/write line, and output
enable line among others. All of the EIM lines operate at 1.8-V logic levels, and the EIM operates at
the MCU clock speed.
Multiple Queue Serial Peripheral Interface (MQSPI)
The Multiple Queue Serial Peripheral Interface (MQSPI) is the MCUs programming interface to other
ICs. The Patriot IC has two independent SPI busses, and each has its own clock line (test points
SCKA and SCKB), data-out line (test points MOSIA and MOSIB), and data-in line (test points MISOA
and MISOB). There are 10 SPI chip selects (SPICS) that are programmable to either SPI A, the
transceiver board SPI bus, or to SPI B, the dedicated VOCON SPI bus.
6881094C31-E
Table 8-2, "List of VOCON Schematics and Board Overlays," on page 8-1
3-19
for a listing
November 16, 2006