Zilog Z08470 - Manual (Page 316)

Z80 Instruction Set UM008007-0715
304
Z80 CPU
User Manual
OUT (C), r
Operation
(C) ← r
Op Code
OUT
Operands
(C), r
Description
The contents of Register C are placed on the bottom half (A0 through A7) of the address
bus to select the I/O device at one of 256 possible ports. The contents of Register B are
placed on the top half (A8 through A15) of the address bus at this time. Then the byte con-
tained in register r is placed on the data bus and written to the selected peripheral device.
Register r identifies any of the CPU registers shown in the following table, which also
shows the corresponding three-bit r field for each that appears in the assembled object
code.
Register r
B 000
C 001
D 010
E 011
H 100
L 101
A 111
M Cycles T States 4 MHz E.T.
3 12 (4, 4, 4) 3.00
1 1 0 0 1 1 1 1 ED
0 1 r 0 0 1