# Test bit in (IX+d)

Undocumented BIT n,(IX+d)

Similar to the RES and SET instructions, there are undocumented instructions for BIT. Unlike the other, as BIT only tests a bit and does not change anything, these opcodes have the same behaviour to the officially documented BIT instruction.

76543210

$$Z \longleftarrow \overline{(IX+d)_b}$$
BIT b, (IX+d)
11011101DD
11001011CB
d
01br

$$Z \longleftarrow \overline{(IY+d)_b}$$
BIT b, (IY+d)
11111101FD
11001011CB
d
01br
Registers
Registerr
B000
C001
D010
E011
H100
L101
A111
Bits
Valueb
0000
1001
2010
3011
4100
5101
6110
7111

Z is set if the specified bit in the source is 0, otherwise it is cleared.

r=%110 does exist, it is the official, documented operation.