DBNZ (SPC700)

Basic Info
Addressing Mode	Opcode	Length	Speed
Direct Page / Program Counter Relative	6E	3 bytes	when condition is false: 5 cycles when condition is true: 7 cycles
Implied (type 1) / Program Counter Relative	FE	2 bytes	when condition is false: 4 cycles when condition is true: 6 cycles

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

DBNZ (Decrement Branch Non-Zero) is an SPC700 instruction that decrements a direct page location or the Y index register and then jumps if that value is nonzero. The direct page index is the first operand and also the first byte immediately following the opcode. The relative branch offset is the second operand, the second byte following the opcode.^[2]

No flags are affected.

Syntax

DBNZ dp, rel
DBNZ Y, rel

See Also

• CBNE
• JNZ

References

1. Official Super Nintendo development manual on DBNZ: Table C-15, Appendix C-8 of Book I
2. anomie's SPC700 doc