SAMSUNG Proprietary-Contents may change without notice
10-2
SCH-A302
Circuit description & Circuit Diagrams
KEY MATRIX
For key recognition, key matrix is setup using KEYSENE0-2 of KEYSENSE signals and KEYSENE0-2 of
input ports of MSM. Ten LEDs and backlight circuitry are included in the board for easy operation in
the dark.
LCD MODULE
LCD module contains a controller which will display the information onto the LCD by 8-bit data from
the MSM.
(3) Baseband Part
MOBILE SYSTEM MODEM (MSM)
The MSM equipped with the QUALCOMM ARM7TDMI µ-processor is an important component of the
CDMA cellular phone. The MSM comes in a 208 pins FBGA package.
MICROPROCESSOR INTERFACE
The interface circuitry consists of reset circuit, address bus(A1-A20), data bus(D1-D16), and memory
controls (~LBE,~UBE,~LWR,~RAM_CS1,~ROM_CS,~RD,~RESIN).
INPUT CLOCK
•
CPU clock: 19.68 MHz, 32.769 kHz(sub-clock)
•
TCXO(pin A17): 19.68 MHz.
This clock signal from the IFR is the reference clock for the MSM
except in CDMA mode.
•
CHIPX8(pin 2G): 9.8304 MHz.
The reference clock used during the CDMA mode.
•
SLEEP-XTAL-IN/OUT(pins R17,T17) : 32.768 MHz
IFR INTERFACE
CDMA, FM Data Interface
•
TXIQDATA0-7 (pins 11, 12, 13, 14, 15, 16, 17, 18):TX data bus used during COMA and FM mode.
•
C_RX_IDATA0-3 (pins 45-48) and C_RX_QDATA0-3 (pins 39-42):RX data bus used during CDMA
mode.
•
FM_RX_IDATA (pin 47) and FM_RX_QDATA (pin 48):RX data bus used during FM mode.
Clock
•
TX_CLK(pin 19), TX_CLK/(pin 20):Analog to Digital Converter(ADC) reference clock used in
TX mode.
•
CHIPX8: ADC reference clock used in CDMA RX mode.
•
FMCLK: Reference clock in FM RX mode.
Data Port Interface
Includes the UART. Also, supports Diagnostic Monitor(DM) and HP equipment interface.
RF Interface
TX: TX_AGC_ADJ(pin 2L) port is used to control the TX power level.
The PA_ON(pin 1P) signal is used to control the power amplifier.
RX: TRK_LO_ADJ(pin 1R) is used to compensate the TCXO clock.
General Purpose I/O Register Pins
Input/output ports to control external devices.
