Renesas SuperH SH-4A, Software Manual

Page: 353 / 472

Rev. 1.50, 10/04, page 333 of 448
10.1.76 SYNCO (Synchronize Data Operation): Data Transfer Instruction
Format Operation Instruction Code Cycle T Bit
SYNCO
Data accesses invoked by the
following instruction are not
executed until execution of
data accesses which precede
this instruction has been
completed.
0000000010101011 Undefined
—
Description: This instruction is used to synchronize data operations. When this instruction is
executed, the subsequent bus accesses are not executed until the execution of all preceding bus
accesses has been completed.
Notes: The SYNCO instruction can not guarantee the ordering of receipt timing which is notified
by the memory-mapped peripheral resources through the method except bus when the register is
changed by bus accesses. Refer to the description of each registers to guarantee this ordering.
Operation:
SYNCO /* SYNCO*/
{
synchronize_data_operaiton();
PC += 2;
}
Example:
1. Ordering access to memory areas which are shared with other memory users
2. Flushing all write buffers
3. Stopping memory-access operations from merging and becoming ineffective
4. Waiting for the completion of cache-control instructions