Bit b, r – Zilog Z08470 User Manual
Page 253
UM008007-0715
Z80 Instruction Description
Z80 CPU
User Manual
241
BIT b, r
Operation
Z ← rb
Op Code
BIT
Operands
b, r
Description
This instruction tests bit b in register r and sets the Z flag accordingly. In the assembled
object code, operands b and r are specified as follows:
Condition Bits Affected
S is unknown.
Z is set if specified bit is 0; otherwise, it is reset.
Bit Tested
b
Register
r
0
000
B
000
1
001
C
001
2
010
D
010
3
011
E
011
4
100
H
100
5
101
L
101
6
110
A
111
7
111
M Cycles
T States
4 MHz E.T.
2
8 (4, 4)
4.50
0
1
b
r
1
1
0
1
1
0
0
1
CB