BIT b,r

Operation

     __
Z <- rb

BIT

b,r

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:

Bit Tested	b	Reg	r	Hex	Reg	Hex	Reg	r	Hex	Reg	r	Hex	Reg	r	Hex	Reg	r	Hex	Reg	r	Hex
0	000	A	111	$47	B	$40	C	001	$41	D	010	$42	E	011	$43	H	100	$44	L	101	$45
1	001	A	111	$4F	B	$48	C	001	$49	D	010	$4A	E	011	$4B	H	100	$4C	L	101	$4D
2	010	A	111	$57	B	$50	C	001	$51	D	010	$52	E	011	$53	H	100	$54	L	101	$55
3	011	A	111	$5F	B	$58	C	001	$59	D	010	$5A	E	011	$5B	H	100	$5C	L	101	$5D
4	100	A	111	$67	B	$60	C	001	$61	D	010	$62	E	011	$63	H	100	$64	L	101	$65
5	101	A	111	$6F	B	$68	C	001	$69	D	010	$6A	E	011	$6B	H	100	$6C	L	101	$6D
6	110	A	111	$77	B	$70	C	001	$71	D	010	$72	E	011	$73	H	100	$74	L	101	$75
7	111	A	111	$7F	B	$78	C	001	$79	D	010	$7A	E	011	$7B	H	100	$7C	L	101	$7D

S	is unknown.
Z	is set if specified bit is 0, otherwise it is reset.
H	is set.
P/V	is unknown
N	is reset.
C	is not affected.

If bit 2 in Register B contains 0, then upon the execution of

	BIT	2,B

the Z flag in the F Register contains 1, and bit 2 in Register B remains at 0. Bit 0 in Register B is the least-significant bit.

Bit Tested	b	Reg	r	Hex	Reg	Hex	Reg	r	Hex	Reg	r	Hex	Reg	r	Hex	Reg	r	Hex	Reg	r	Hex
0	000	A	111	$47	B	$40	C	001	$41	D	010	$42	E	011	$43	H	100	$44	L	101	$45
1	001	A	111	$4F	B	$48	C	001	$49	D	010	$4A	E	011	$4B	H	100	$4C	L	101	$4D
2	010	A	111	$57	B	$50	C	001	$51	D	010	$52	E	011	$53	H	100	$54	L	101	$55
3	011	A	111	$5F	B	$58	C	001	$59	D	010	$5A	E	011	$5B	H	100	$5C	L	101	$5D
4	100	A	111	$67	B	$60	C	001	$61	D	010	$62	E	011	$63	H	100	$64	L	101	$65
5	101	A	111	$6F	B	$68	C	001	$69	D	010	$6A	E	011	$6B	H	100	$6C	L	101	$6D
6	110	A	111	$77	B	$70	C	001	$71	D	010	$72	E	011	$73	H	100	$74	L	101	$75
7	111	A	111	$7F	B	$78	C	001	$79	D	010	$7A	E	011	$7B	H	100	$7C	L	101	$7D

Bit Tested	b	Reg	r	Hex	Reg	Hex	Reg	r	Hex	Reg	r	Hex	Reg	r	Hex	Reg	r	Hex	Reg	r	Hex
0	000	A	111	$47	B	$40	C	001	$41	D	010	$42	E	011	$43	H	100	$44	L	101	$45
1	001	A	111	$4F	B	$48	C	001	$49	D	010	$4A	E	011	$4B	H	100	$4C	L	101	$4D
2	010	A	111	$57	B	$50	C	001	$51	D	010	$52	E	011	$53	H	100	$54	L	101	$55
3	011	A	111	$5F	B	$58	C	001	$59	D	010	$5A	E	011	$5B	H	100	$5C	L	101	$5D
4	100	A	111	$67	B	$60	C	001	$61	D	010	$62	E	011	$63	H	100	$64	L	101	$65
5	101	A	111	$6F	B	$68	C	001	$69	D	010	$6A	E	011	$6B	H	100	$6C	L	101	$6D
6	110	A	111	$77	B	$70	C	001	$71	D	010	$72	E	011	$73	H	100	$74	L	101	$75
7	111	A	111	$7F	B	$78	C	001	$79	D	010	$7A	E	011	$7B	H	100	$7C	L	101	$7D

Bit Tested	b	Reg	r	Hex	Reg	Hex	Reg	r	Hex	Reg	r	Hex	Reg	r	Hex	Reg	r	Hex	Reg	r	Hex
0	000	A	111	$47	B	$40	C	001	$41	D	010	$42	E	011	$43	H	100	$44	L	101	$45
1	001	A	111	$4F	B	$48	C	001	$49	D	010	$4A	E	011	$4B	H	100	$4C	L	101	$4D
2	010	A	111	$57	B	$50	C	001	$51	D	010	$52	E	011	$53	H	100	$54	L	101	$55
3	011	A	111	$5F	B	$58	C	001	$59	D	010	$5A	E	011	$5B	H	100	$5C	L	101	$5D
4	100	A	111	$67	B	$60	C	001	$61	D	010	$62	E	011	$63	H	100	$64	L	101	$65
5	101	A	111	$6F	B	$68	C	001	$69	D	010	$6A	E	011	$6B	H	100	$6C	L	101	$6D
6	110	A	111	$77	B	$70	C	001	$71	D	010	$72	E	011	$73	H	100	$74	L	101	$75
7	111	A	111	$7F	B	$78	C	001	$79	D	010	$7A	E	011	$7B	H	100	$7C	L	101	$7D