OUT
OUTPUTOUT
Operation:
(DEST) - (SRC)
Description:
OUT port,accumulator
OUT transfers a byte or a word from the AL register or the AX register, respectively, to an output port. The port number may be speci- fied either with an immediate byte constant, allowing access to ports numbered 0 through
Flags Affected:
None
255, or with a number previously placed in register DX, allowing variable access (by changing the value in DX) to ports numbered from 0 through 65,535.
Encoding:
Fixed Port:
1111 00 11 w 1 port
if w = 0 then else SRC =
SRC = AL, DEST = port AX, DEST = port + 1:port
Variable Port:
11110111wl
if w = 0 then else SRC =
SRC = AL, DEST = (DX) AX, DEST = (DX) + 1:(DX)
OUT Operands | Clocks* | Transfers | Bytes | OUT Coding Example |
immed8, accuml,Jlator | 10(14) | 1 | 2 | OUT 44, AX |
DX, accumulator | 8(12) | 1 | 1 | PUT DX, AL |
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*b(w): where b denotes the number of clock cycles for byte operands and w denotes the number of clock cycles for word operands.
