C905
1222-9526 rev. 1
FUNCTIONAL OVERVIEW
FU
N
C
T
IO
N
A
L O
V
E
R
V
IE
W
Technical Description
Digital Baseband Controller (CPU)
N2010 (Kajsa)
This component is not replaceable on SL 4 because Baseband calibration is required.
The Digital Baseband Controller is divided in two subsystems: Access and Application
Access Subsystem
All modem functionality in the digital baseband controller resides in the Access
subsystem. This includes EDGE/GPRS/GSM interface, WCDMA interface, USB, IrDA, and
other peripheral modules. The control CPU is an ARM926 and a DSP is used for signal
processing and layer one control code.
The main communication between the blocks in the Access subsystem is done through
the Advanced High-performance Bus (AHB) matrix, which is a set of control buses
connecting the different parts together. A block called Syscon is responsible for
distributing clocks and resets to all parts of the Access subsystem. This block is under
SW control. The Access subsystem is connected to the Shared EMIF, an interface for
communication with an external SDRAM. The Shared EMIF is shared between the Access
subsystem and the Application subsystem.
Access Subsystem:
Application Subsystem
The Application subsystem contains functionality related to functions such as MMI,
graphics, audio and memory media. The control CPU is an ARM926 with three external
memory interfaces, one shared with the Access subsystem and two dedicated for the
Application subsystem. The Application subsystem contains several blocks. The main
communication between the blocks is done through the Advanced High performance bus
(AHB) matrix, which is a set of control buses connecting the different parts. A block
called Syscon is responsible for distributing clocks and resets to all parts of the
Application subsystem. This block is under SW control. The Application subsystem is
connected to the Shared EMIF that is used for code execution or data storage. In
addition, a dedicated EMIF that support SDRAM or static memory like NOR, PsRAM or
NAND are also available. The Application EMIF is a general interface for communication
with, for example external SDRAM, PSRAM, NOR flash, NAND flash and companion chips
Application Subsystem:
SEMC Troubleshooting Manual
92
(124)
