5-142
Z380
™
U
SER
'
S
M
ANUAL
DC-8297-03
Z
ILOG
RETI
RETURN FROM INTERRUPT
RETI
Operation:
if (XM) then begin
PC(7-0)
←
(SP)
PC(15-8)
←
(SP+1)
PC(23-16)
←
(SP+2)
PC(31-24)
←
(SP+3)
SP
←
SP + 4
end
else begin
PC(7-0)
←
(SP)
PC(15-8)
←
(SP+1)
SP
←
SP + 2
end
This instruction is used to return to a previously executing procedure at the end of a
procedure entered by an interrupt. The contents of the location addressed by the Stack
Pointer (SP) are popped into the Program Counter (PC), thereby specifying the location of
the next instruction to be executed. A special sequence of bus transactions is performed
when this instruction is executed in order to control Z80 family peripherals; see the
description of the external interface for more details.
Flags:
S:
Unaffected
Z:
Unaffected
H:
Unaffected
V:
Unaffected
N:
Unaffected
C:
Unaffected
Addressing
Execute
Mode
Syntax
Instruction Format
Time
Note
RETI
11101101 01001101
2+r
X