Instruction Syntax

Mnemonic	Format	Flags
mfsrr1	rD	None

Instruction Encoding

Field	Bits	Description
Primary Opcode	0-5	011111 (0x1F)
rD	6-10	Destination register
rA	11-15	00000 (unused)
rB	16-20	00000 (unused)
XO	22-29	01010110 (0x56)

Operation

rD ← SRR1

MFSRR1 copies the contents of the Save/Restore Register 1 (SRR1) into the destination register rD.

1. Reads the value from the Save/Restore Register 1 (SRR1)
2. Copies it to the destination register rD

Note: SRR1 contains the machine state information that was saved when the exception occurred.

Affected Registers

General Purpose Registers (GPRs)

• rD (Destination register) - Loaded with SRR1 value

Examples

Basic SRR1 Read

# Read the Save/Restore Register 1
mfsrr1 r3          # r3 = SRR1

Exception Handler

# In an exception handler
exception_handler:
mfsrr1 r3          # Get the saved machine state
# Process the exception using the state information in r3

Debug Information

# Get machine state for debugging
mfsrr1 r10         # Save machine state
# Log or process the state for debugging

Related Instructions

mtsrr1 (Move to SRR1), mfsrr0 (Move from SRR0), mtsrr0 (Move to SRR0), mfdar (Move from DAR)