RETIcond
Return From Interrupt Conditionally
13-198
Syntax
RETI
cond
Operation
If
cond is true:
*SP – –
→
PC
1
→
ST (GIE).
Else, continue.
Operands
None
Opcode
31
24 23
16
8 7
0
15
0 1 1 1 1
0
0
0
0
cond
0
0 0
0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0
Description
A conditional return is performed. If the condition is true, the top of the stack
is popped to the PC, and a 1 is written to the global interrupt enable (GIE) bit
of the status register. This has the effect of enabling all interrupts for which the
corresponding interrupt enable bit is a 1.
The ’C3x provides 20 condition codes that can be used with this instruction
(see Table 13–12 on page 13-30 for a list of condition mnemonics, condition
codes, and flags). Condition flags are set on a previous instruction only when
the destination register is one of the extended-precision registers (R7–R0) or
when one of the compare instructions (CMPF, CMPF3, CMPI, CMPI3, TSTB,
or TSTB3) is executed.
Cycles
4
Status Bits
LUF
Unaffected
LV
Unaffected
UF
Unaffected
N Unaffected
Z
Unaffected
V
Unaffected
C
Unaffected
OVM
Operation is not affected by OVM bit value.
Mode Bit