26-06-2012, 06:08 PM
ARM
ARM_1.ppt (Size: 933 KB / Downloads: 166)
What Is ARM?
Advanced RISC Machine
First RISC microprocessor
for commercial use
Market-leader for low-power
and cost-sensitive embedded applications
The History of ARM
Developed at Acorn Computers Limited,
of Cambridge, England,
between 1983 and 1985
Problems with CISC:
Slower then memory parts
Clock cycles per instruction
ARM Architecture
Typical RISC architecture:
Large uniform register file
Load/store architecture
Simple addressing modes
Uniform and fixed-length instruction fields
Pipeline Organization
Increases speed –
most instructions executed in single cycle
Versions:
3-stage (ARM7TDMI and earlier)
5-stage (ARMS, ARM9TDMI)
6-stage (ARM10TDMI)
ARM Registers
Special roles:
Hardware
R14 – Link Register (LR):
optionally holds return address
for branch instructions
R15 – Program Counter (PC)
Software
R13 - Stack Pointer (SP)