Introduction
84
SPRUH82C – April 2013 – Revised September 2016
Copyright © 2013–2016, Texas Instruments Incorporated
ARM Subsystem
2.1
Introduction
This chapter describes the ARM subsystem and its associated memories. The ARM subsystem consists of
the following components:
•
ARM926EJ-S™ 32-bit RISC CPU
•
16-KB Instruction cache
•
16-KB Data cache
•
Memory Management Unit (MMU)
•
Co-Processor 15 (CP15) to control MMU, cache, etc.
•
Jazelle™ Java Accelerator
•
ARM Internal Memory
–
8 KB RAM
–
64 KB built-in ROM
•
Embedded Trace Module and Embedded Trace Buffer (ETM/ETB)
•
Features:
–
The main write buffer has a 16-word data buffer and a 4-address buffer
–
Support for 32-bit ARM/16-bit THUMB instruction sets
–
Fixed little-endian memory format
The ARM926EJ-S processor is a member of the ARM9 family of general-purpose microprocessors. The
ARM926EJ-S processor targets multi-tasking applications where full memory management, high
performance, low die size, and low power are all important.
The ARM926EJ-S processor supports the 32-bit ARM and the 16-bit THUMB instruction sets, enabling
you to trade off between high performance and high code density. This includes features for efficient
execution of Java byte codes and providing Java performance similar to Just in Time (JIT) Java interpreter
without associated code overhead.
The ARM926EJ-S processor supports the ARM debug architecture and includes logic to assist in both
hardware and software debugging. The ARM926EJ-S processor has a Harvard architecture and provides
a complete high performance subsystem, including the following:
•
An ARM926EJ-S integer core
•
A Memory Management Unit (MMU)
•
Separate instruction and data Advanced Microcontroller Bus Architecture (AHBA) Advanced High
Performance Bus (AHB) bus interfaces
NOTE:
There is no TCM memory and interface on this device.
The ARM926EJ-S processor implements ARM architecture version 5TEJ.
The ARM core also has 8 KB RAM (typically used for vector table) and 64 KB ROM (for boot images)
associated with it. The RAM/ROM locations are not accessible by any other master peripherals.
Furthermore, the ARM has DMA and CFG bus master ports via the AHB interface.