LG U8110 Service Manual page 23

3. TECHNICAL BRIEF
G. System Control Subsystem
The system controller subsystem (SYSCON) is primarily responsible for generating clock signals and
distributing the clock and reset signals within the ASIC and certain external devices. The GSM core,
GAM and DSP subsystems include their own system controllers that are sourced from SYSCON.
SYSCON consists of analog and digital PLL clocks and a clock squarer. The block is a slave
peripheral on the slow APB bus under control of the CPU.
The programming of SYSCON controls the fundamental modes of operation within the ASIC.
Individual blocks can also be reset and their clocks held inactive by accessing the appropriate control
registers. SYSCON also controls the requesting protocol through which different sub-blocks in
Ericsson DB 20000 can request clocks derived from the system clock.
The system controller also stores the chip-ID number in a read only register.
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