AD20msp415

–6–

REV. 0

Digital Interface from the GSMP to Accessories

To allow proper control of external accessories like a car kit, the

AD6422 provides a 10-pin accessory interface comprised of

eight general purpose I/O channels, one chip select and one

power control signal.

Digital Test Interface

The AD6421 and the AD6422 both support advanced test

methodologies by providing JTAG Boundary Scan. Addition-

ally, the AD6422 provides Test/Mode pins, which select differ-

ent test and operating modes.

Digital Interface from GSMP to Optional EFR-Coprocessor

The AD6422 provides a digital interface to an external EFR

Coprocessor (DSP). This coprocessor is required to handle the

Enhanced Full Rate speech codec in PCS1900 mobile radios.

Baseband Processing Key Parts List

Table I lists the major hardware components necessary to com-

plete the GSM baseband processing subsystem.

DISPLAY

CONTROL

KEYPAD

EEPROM

DATA

INTERFACE

VBC

CLOCK

POWER

SUBSYSTEM

13MHz

VCTCXO

DAI

INTERFACE

GSMP

SYNTHESIZER

AND RADIO

CONTROL

DEMODULATOR

MODULATOR

IF

AMPLIFIER

RADIO

POWER

AMPLIFIER

CAR KIT

VOICEBAND

ANALOG I/O

RAMP DAC

AGC DAC

BASEBAND

ANALOG I/O

AUX ADC

SERIAL

PORTS

AFC DAC

DAI CONTROL

VBC INTERFACE

POWER

CONTROL

SYNTHESIZER

AND RADIO

CONTROL

DATA

INTERFACE

EEPROM

INTERFACE

KEYPAD

INTERFACE

BACKLIGHT

CONTROL

DISPLAY

CONTROL

DATA

ADDRESS

SIM

INTERFACE

BACKLIGHT

SRAM

FLASH

SIM CARD

TEST

INTERFACE

TEST

INTERFACE

CLKIN

ACCESSORIES

CLKOUT

MCLK

COPROCESSOR

(OPTIONAL)

COPROCESSOR

INTERFACE

Figure 5. Chipset Interfaces

Table I. List of Key Components

Description

Specification

GSMP

1

AD6422

VBC

1

AD6421

EFR-Coprocessor

2

AD6423

FLASH

3

256K

× 16, 150 ns

SRAM

128K

× 8, 120 ns

EEPROM

4

2K

× 8

Display Driver

Design Specific

NOTES

chipset.

requiring support of the Enhanced Full Rate speech

codec.

all GSM Layer (1, 2, 3) programs for GSM Phase 2

as well as a typical User Interface (MMI).

memory.