Bit bit test – Zilog Z80380 User Manual
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Z380
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ANUAL
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ILOG
DC-8297-03
BIT
BIT TEST
BIT b,dst
dst = R, IR, X
Operation:
Z
←
NOT dst(b)
The specified bit b within the destination operand is tested, and the Zero flag is set to 1 if
the specified bit is 0, otherwise the Zero flag is cleared to 0. The contents of the destination
are unaffected. The bit to be tested is specified by a 3-bit field in the instruction; this field
contains the binary encoding for the bit number to be tested. The bit number b must be
between 0 and 7.
Flags:
S:
Unaffected
Z:
Set if the specified bit is zero; cleared otherwise
H:
Set
V:
Unaffected
N:
Cleared
C:
Unaffected
Addressing
Execute
Mode
Syntax
Instruction Format
Time
Note
R:
BIT b,R
11001011 01bbb-r-
2
IR:
BIT b,(HL)
11001011 01bbb110
2+r
X:
BIT b,(XY+d)
11y11101 11001011 ——d— 01bbb110
4+r
I
Field Encodings:
r:
per convention
y:
0 for IX, 1 for IY