2.1
Purpose of the ARM Subsystem
2.2
Components of the ARM Subsystem
SPRUFX7 – July 2008
ARM Subsystem Overview
The ARM Subsystem contains components required to provide the ARM926EJ-S (ARM) master control of
the overall device system, including control over the VPSS Subsystem, the peripherals, and external
memories.
The ARM is responsible for handling system functions such as system-level initialization, configuration,
user interface, user command execution, connectivity functions, etc. The ARM is master and performs
these functions because it has a large program memory space and fast context switching capability, and is
thus suitable for complex, multi-tasking, and general-purpose control tasks.
The ARM Subsystem (ARMSS) in the device consists of the following components:
•
ARM926EJ-S RISC processor, including:
–
Coprocessor 15 (CP15)
–
MMU
–
16KB Instruction cache
–
8KB Data cache
–
Write Buffer
–
Java accelerator
•
ARM Internal Memories
–
32KB Internal RAM (32-bit wide access)
–
8KB Internal ROM (ARM bootloader for non-AEMIF boot options)
•
Embedded Trace Module and Embedded Trace Buffer (ETM/ETB)
•
System Control Peripherals
–
ARM Interrupt Controller
–
PLL Controller
–
Power and Sleep Controller
–
System Module
The ARM also manages/controls the following peripherals:
•
DDR2 EMIF Controller
•
AEMIF Controller, including the NAND flash interface
•
Enhanced DMA (EDMA)
•
UART (There are three UARTs supported in the device)
•
Timers
•
Real Time Out (RTO)
•
Pulse Width Modulator (PWM)
•
Inter-IC Communication (I2C)
•
Multi-Media Card/Secure Digital (MMC/SD)
•
Audio Serial Port (ASP)
•
Universal Serial Bus Controller (USB)
•
Serial Port Interface (SPI)
18
ARM Subsystem Overview
SPRUFX7 – July 2008