Idle — Idle Operation - Samsung S3F84B8 User Manual

S3F84B8_UM_REV 1.00
6.3.29 IDLE — IDLE OPERATION
IDLE
Operation:
The IDLE instruction stops the CPU clock while allowing the system clock oscillation to continue.
Idle mode can be released by an interrupt request (IRQ) or an external reset operation.
In application programs, an IDLE instruction must be immediately followed by at least three NOP
instructions. This ensures an adequate time interval for the clock to stabilize before the next
instruction is executed. If three or more NOP instructions are not used after IDLE instruction,
leakage current could be flown because of the floating state in the internal bus.
No flags are affected.
Flags:
Format:
opc
The instruction
Example:
IDLE
NOP
NOP
NOP
; stops the CPU clock but not the system clock
6-42
Bytes Cycles Opcode
1 4
6 INSTRUCTION SET
Addr Mode
(Hex) dst src
6F – –