sync
Synchronize - 4C 00 00 64
sync
Instruction Syntax
| Mnemonic | Format | Flags |
| sync | None | None |
Instruction Encoding
0
1
0
0
1
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
0
0
1
0
0
| Field | Bits | Description |
| Primary Opcode | 0-5 | 010011 (0x13) |
| Reserved | 6-10 | 00000 |
| Reserved | 11-15 | 00000 |
| Reserved | 16-20 | 00000 |
| Reserved | 21-29 | 000000000 |
| Reserved | 30-31 | 00 |
Operation
Wait for all previous memory operations to complete
The sync instruction ensures that all memory operations issued before the sync instruction have completed before any memory operations after the sync instruction are issued.
Note: The sync instruction is used to enforce memory ordering in multiprocessor systems and to ensure that memory operations are visible to other processors.
Affected Registers
None
The sync instruction does not affect any registers.
Examples
Basic Synchronization
sync # Wait for all previous memory operations to complete
Memory Barrier
# Ensure memory operations are visible to other processors stw r3, 0(r4) # Store value to memory sync # Synchronize memory operations lwz r5, 8(r4) # Load value from memory
Multiprocessor Coordination
# Coordinate between processors stw r3, flag_addr # Set flag sync # Ensure flag is visible to other processors # Continue with next operation