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V
V
I
I
T
T
E
E
L
L
C
C
O
O
M
M
M
M
O
O
B
B
I
I
L
L
E
E
T
T
E
E
C
C
H
H
N
N
O
O
L
L
O
O
G
G
Y
Y
S
S
.
.
A
A
.
.
MSM(U125) Internal Block
1) ARM Microprocessor Subsystem
The MSM(U125) uses an embedded ARM7TDMI microprocessor. The ARM7TDMI microprocessor,
through the system software, controls most of the functionality for the Mobile Station, including control of
the external peripherals such as the keypad, LCD display, RAM and ROM/FLASH(U113) devices.
2) RF Interface
This block communicates with the MSM(U125) RF, IF and Analog Base-band circuitry.
3) CDMA Subsystem: Digital IS-2000 Signal Processing.
Searcher engine
Demodulating fingers
Combining block
Frame de-interleaver
Viterbi decoder
Reverse link subsystem
4) UART (Universal Asynchronous Receiver Transmitter)
Two identical UARTs, UART1 has dedicated pins while UART2 share multiplexed pins with the Auxiliary
PCM CODEC interface.
5) Vocoder Subsystem
The MSM(U125)’s QDSP2000 supports EVRC and QCELP13K vocoders. In addition, the QDSP2000 has
modules to support the following audio functions; DTMF tone generation, DTMF tone detection, Tx/Rx
volume controls, Tx/Rx automatic gain control(AGC), Rx Automatic Volume Control(AVC), Ear Seal Echo
Canceller(ESEC), Acoustic Echo Canceller(AEC), Noise Suppression(NS), and programmable, 13-tap,
Type-I, FIR, Tx/Rx compensation filters. The MSM(U125)’s integrated ARM7TDMI processor downloads
the firmware into the QDSP2000 and configures QDSP2000 to support the desired functionality.
6) General Purpose Interface Bus
The MSM(U125) has 48 general-purpose bi-directional input/output pins (GPIO_INT[47:0]) that double as
general-purpose interrupt inputs. Some of the GPIO_INT pins have alternate functions supported on them.
The alternate functions include, USB interface, additional RAM, ROM/Flash(U113), general-purpose chip
selects, parallel LCD interface, and a UART interface. The function of these pins is documented in the
various software releases.
7) Serial Bus Interface
