Motorola DSP96002 - Manual (Page 499)

MOTOROLA DSP96002 USER’S MANUAL A - 311
WAIT Wait for Interrupt WAIT
Instruction Fields:
None
Timing: n/a
Memory: 1 program words
Operation:
Enter WAIT processing state and stop all internal processing.
Wait for an unmasked interrupt to occur.
Assembler Syntax:
WAIT
Description:
When a WAIT instruction is executed, the processor enters the WAIT state. The internal clocks to the pro-
cessor core, memories, and DMA are gated off and all activity in the processor is suspended until an un-
masked interrupt occurs. However the clock oscillator and the internal I/O peripheral clocks remain active.
If WAIT is executed when an interrupt is pending, the interrupt will be processed; the effect will be the same
as if the processor never entered the WAIT state and three NOPs followed the WAIT instruction. When an
unmasked interrupt or external (hardware) processor RESET occurs, the processor leaves the WAIT state.
The WAIT state is then cleared and exception processing of the unmasked interrupt or RESET condition
begins. The
—
B
–
R/
—
B
–
G circuits remain active during the WAIT state. The WAIT state is a low-power
standby mode. The processor always leaves the WAIT state in the T2 clock phase (see the DSP96002 Ad-
vance Information Data Sheet (DSP96002/D)). Therefore, multiple processors may be synchronized by
having them all enter the WAIT state and then interrupting them with a common interrupt.
CCR Condition Codes: Not affected.
ER Status Bits: Not affected.
IER Flags: Not affected.
Instruction Format: WAIT
00 0000 0000 1110
31 14 13 0
0000 0000 0000 0000 00