Atmel ARM-Based Evaluation Kit AT91SAM9N12-EK AT91SAM9N12-EK Data Sheet

Product codes
AT91SAM9N12-EK
Page of 248
Introduction 
1-2
Copyright © 2001-2003 ARM Limited. All rights reserved.
ARM DDI0198D
1.1
About the ARM926EJ-S processor
The ARM926EJ-S processor is a member of the ARM9 family of general-purpose 
microprocessors. The ARM926EJ-S processor is targeted at 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 16-bit Thumb instruction 
sets, enabling the user to trade off between high performance and high code density. The 
ARM926EJ-S processor includes features for efficient execution of Java byte codes, 
providing Java performance similar to JIT, but without the associated code overhead. 
The ARM926EJ-S processor supports the ARM debug architecture and includes logic 
to assist in both hardware and software debug. The ARM926EJ-S processor has a 
Harvard cached architecture and provides a complete high-performance processor 
subsystem, including:
an ARM9EJ-S integer core
Memory Management Unit (MMU)
separate instruction and data AMBA AHB bus interfaces
separate instruction and data TCM interfaces.
The ARM926EJ-S processor provides support for external coprocessors enabling 
floating-point or other application-specific hardware acceleration to be added. The 
ARM926EJ-S processor implements ARM architecture version 5TEJ. 
The ARM926EJ-S processor is a synthesizable macrocell. This means that you can 
optimize the macrocell for a particular target library, and that you can configure the 
memory system to suit your target application. You can individually configure the cache 
sizes to be any power of two between 4KB and 128KB. 
The tightly-coupled instruction and data memories are instantiated externally to the 
ARM926EJ-S macrocell, providing you with the flexibility of optimizing the memory 
subsystem for performance, power, and particular RAM type. The TCM interfaces 
enable nonzero wait state memory to be attached, as well as providing a mechanism for 
supporting DMA.
Figure 1-1 on page 1-3 shows the main blocks in the ARM926EJ-S processor.