LG C2100, Service Manual

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3. TECHNICAL BRIEF
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3.5.2 AD6527 Architecture
The internal architecture of AD6527 is shown above Figure 3-10. AD6527 regroups three main
subsystems connected together through a dynamic and flexible communication bus network. It also
includes onboard system RAM (SRAM) and interfaces with external Flash Memory, Baseband
converter functions, and terminal functions like MMI, SIM and Universal System Connector (USC).
The Digital Signal Processing (DSP) subsystem primarily hosts all the speech processing, channel
equalization and channel codec functions. The code used to implement such functions can be stored
in external Flash Memory and dynamically downloaded on demand into the DSP’s program RAM and
Instruction Cache.
The micro-controller subsystem supports all the GSM terminal software, including the layer 1, 2 and 3
of the GSM protocol stack, the MMI, and applications software such as data services, test and
maintenance. It is tightly associated with on-chip system SRAM and also includes boot ROM memory
with a small dedicated routine to facilitate the initialization of the external Flash Memory via code
download using the on-chip serial interface to the external Flash Memory interface.
The peripheral subsystem is composed of system peripherals such as interrupt controller, real time
clock, watch dog timer, power management and a timing and control module. It also includes
peripheral interfaces to the terminal functions: keyboard, battery supervision, radio and display. Both
the DSP and the MCU can access the peripheral subsystem via the peripheral bus (PBUS).
For program and data storage, both the MCU subsystem and the DSP subsystem can access the on
chip system SRAM and external memory such Flash Memory. The access to the SRAM module is
made through the RAM Bus (RBUS) under the control of the bus arbitration logic. Similarly, access to
the Flash Memory is through the parallel External Bus (EBUS).
AD6527/AD6527B AD6527/AD6527B
DSP
Subststem
DSP
Subststem
PBUS PBUS
DSP BUS DSP BUS
SErial Link SErial Link
SBUS SBUS
PBUS 1M PBUS 1M
EBUS EBUS
AS6535
Audio Baseband
and Power
Management
AS6535
Audio Baseband
and Power
Management
DMA and BUS
ARBITRATION
DMA and BUS
ARBITRATION
Peripheral
Subsystem
Peripheral
Subsystem
SRAM SRAM
FLASH FLASH
RF-Control
MMI
USC
RF-Control
MMI
USC
Figure 3-10. AD6527 Architecture