24
Rabbit 2000/3000 Microprocessor
Description
Tests the bit b (any of the bits 0, 1, 2, 3, 4, 5, 6, or 7) of the byte in the register r (any of the registers A, B, C,
D, E, H, or L).
The Zero Flag, Z, is set if the tested bit is 0, reset if the bit is 1.
Description
If the data in word register HL does not equal zero, then it is set to 1. This instruction is implemented for the
Rabbit and is not available for the Z180.
BIT b,r
Opcode
Instruction
Clocks
Operation
b,r
A
B
C
D
E
H
L
BIT b,r
4(2,2)
r & bit
CB (0)
47
40
41
42
43
44
45
CB (1)
4F
48
49
4A
4B
4C
4D
CB (2)
57
50
51
52
53
54
55
CB (3)
5F
58
59
5A
5B
5C
5D
CB (4)
67
60
61
62
63
64
65
CB (5)
6F
68
69
6A
6B
6C
6D
CB (6)
77
70
71
72
73
74
75
CB (7)
7F
78
79
7A
7B
7C
7D
Flags
ALTD
I/O
S
Z
L/V
C
F
R
SP
S
D
-
•
-
-
•
BOOL HL
Opcode
Instruction
Clocks
Operation
CC
BOOL HL
2
If (HL != 0) HL = 1
Flags
ALTD
I/O
S
Z
L/V
C
F
R
SP
S
D
•
•
0
0
•
•
Summary of Contents for 2000
Page 2: ...ii Rabbit 2000 3000 Microprocessor...
Page 4: ...iv Rabbit 2000 Microprocessor...
Page 16: ...12 Rabbit 2000 3000 Microprocessor...
Page 112: ...108 Rabbit 2000 3000 Microprocessor...
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