BBS (SPC700)

Basic Info
Addressing Mode	Opcode	Length	Speed
Direct Page	03	3 bytes	when condition false: 5 cycles when condition true: 7 cycles
Direct Page	23	3 bytes	when condition false: 5 cycles when condition true: 7 cycles
Direct Page	43	3 bytes	when condition false: 5 cycles when condition true: 7 cycles
Direct Page	63	3 bytes	when condition false: 5 cycles when condition true: 7 cycles
Direct Page	83	3 bytes	when condition false: 5 cycles when condition true: 7 cycles
Direct Page	A3	3 bytes	when condition false: 5 cycles when condition true: 7 cycles
Direct Page	C3	3 bytes	when condition false: 5 cycles when condition true: 7 cycles
Direct Page	E3	3 bytes	when condition false: 5 cycles when condition true: 7 cycles

Flags Affected
N	V	P	B	H	I	Z	C
.	.	.	.	.	.	.	.

BBS (Branch on Bit Set) is an SPC700 instruction that performs a branch when a bit in the direct page is set. The index to the direct page byte that bit lives in is the first operand byte. Which bit within that byte is a specified by the top 3 bits of the opcode. The target relative address to jump to is the second operand byte.

In assembly source, the two operands appear in the same order that they do in the instruction stream.

See Also

• BBC

References

• Table C-15, Appendix C-8 of Book I of the official Super Nintendo development manual