Motorola ASTRO XTSTM 4000 Detailed Service Manual Download

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6871620L01-C

May 28, 2008

VOCON Section

3-19

3.2.3.1 MAKO IC U1304

The MAKO IC is a mixed-signal (analog and digital) IC that provides control, audio, and voltage
regulation functionality. It comes in a 176-pin, ball-grid array (BGA) package with 0.8 mm pitch solder
balls. The MAKO IC is supplied with switched battery voltage (R1309).

3.2.3.1.1 Voltage Regulation

The MAKO IC contains several voltage regulators that are used in the design of the VOCON section:
VSW1, V2, VCC5, V1.55 and V1.875. The VSW1 regulator is a programmable switching regulator
that uses the switched battery voltage as its input. The output voltage of VSW1 (R1319) is
programmable by the Patriot IC U1401 through the SPI bus. The initial output of VSW1 is 3.2 volts,
which is then programmed to 3.8 volts. The VSW1 voltage is supplied to the RF transceiver section
and to the input pins of the V2 regulator.

The V2 regulator is a SPI programmable linear regulator that uses VSW1 as its supply. The initial
output of V2 (L1302) is 2.775 volts, which is then programmed to 2.9 volts for the VOCON section.
The V2 voltage is supplied to the Patriot IC (I/O ring - SPI, BBP, SAP, UART, GPIO, etc.), the display
module via connector J1, and the many discrete components that interface with the Patriot IC and
the MAKO IC.

The VCC5 regulator is a fixed linear regulator that outputs 5Vdc. VCC5 is used by the accessory I/O
lines and the audio switch U20.

The V1.55 is a SPI programmable linear regulator. V1.55 is used by the Patriot MCU Core. The
V1.875 is a SPI programmable linear regulator. V1.875 is used by the EIM, Memory, Display and I/O
ring.

3.2.3.1.2 MCU Interface

The MAKO IC has a four-wire, SPI connection to the Patriot IC (SPI B). The SPI B clock is connected
to the SPI_CLK pin (SCKB). The SPI B MOSI line is connected to the SPI_DI pin. The SPI B MISO
line is connected to the SPI_DO pin. The MAKO SPI B chip-select signal is connected to the SPI_CS
pin (R1334). Through this interface, the Patriot IC can program the voltage regulators, the CODEC,
the transmit and receive audio filters and amplifiers, as well as read information from the ADC and
the real-time clock.

The MAKO IC has an 10-bit ADC with 11 channels. Some of the ADC channels are used for general
purpose voltage monitoring: Emergency Button (ATOD_2), board type (ATOD_5) and the board
identification voltage (ATOD_6). Battery voltage is also monitored by the ADC. The Patriot IC
activates and reads the A/D values through the SPI bus.

3.2.3.1.3 Audio Circuitry

A 16-bit CODEC, internal to the MAKO IC and programmable by the Patriot IC through the SPI bus,
converts microphone audio into a digital bit stream for processing by the DSP. The CODEC also
converts receive audio data that was processed by the DSP into an analog audio signal for
amplification to a speaker. The CODEC interfaces to the DSP through the 4-wire SAP bus. The
CODEC clock, which is 256 kHz is supplied to the DCLK pin. The CODEC 8 kHz CODEC frame
synchronization signal is supplied to the FSYNC pin. The CODEC transmit data signal is on the TX
pin, while the CODEC receive data signal is on the RX pin. For the CODEC to operate with those
clock and frame sync signals, a 24.576MHz clock, generated by Y1302 is supplied to the MAKO IC.

The MAKO IC contains internal amplification, filtering, and multiplexing functionality for both receive
and transmit audio. These functions are Patriot IC-programmable through the SPI bus. The input for
the internal microphone audio (C1350) is the INT_MIC_P pin, while the input for the external
microphone audio (C1347) is the EXT_MIC_P pin.