Mips Technologies R4000 - CPU Register Overview

Chapter 1
12 MIPS R4000 Microprocessor User's Manual
CPU Register Overview
The central processing unit (CPU) provides the following registers:
• 32 general purpose registers
• a Program Counter (PC) register
• 2 registers that hold the results of integer multiply and divide
operations (HI and LO).
Floating-point unit (FPU) registers are described in Chapter 6.
CPU registers can be either 32 bits or 64 bits wide, depending on the R4000
processor mode of operation.
Figure 1-2 shows the CPU registers.
Figure 1-2 CPU Registers
r0
r1
r2
r31
Multiply and Divide Registers
Program Counter
31 0
31 0
31 0
HI
LO
31 0
General Purpose Registers
PC
•
•
•
•
r29
r30
63
63
63
63
Register width depends on mode of operation: 32-bit or 64-bit
32
32
32
32