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CBNE (SPC700): Difference between revisions
From SnesLab
(see also DBNZ) |
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!colspan="8"|Basic Info | !colspan="8"|Basic Info | ||
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|'''Speed''' | |'''Speed''' | ||
|+ | |+ | ||
| | |[[Direct Page]] / [[Program Counter Relative]] | ||
|2E | |2E | ||
|3 bytes | |3 bytes | ||
|5 | |when condition is false: 5 cycles | ||
when condition is true: 7 cycles | |||
|+ | |+ | ||
| | |[[Direct Page Indexed by X]] / [[Program Counter Relative]] | ||
|DE | |DE | ||
|3 bytes | |3 bytes | ||
|6 | |when condition is false: 6 cycles | ||
when condition is true: 8 cycles | |||
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!colspan="8"|Flags | !colspan="8"|Flags Affected | ||
|+ | |+ | ||
|N | |[[Negative Flag|N]] | ||
|V | |[[Overflow Flag|V]] | ||
|P | |[[Direct Page Flag|P]] | ||
|B | |[[Break Flag|B]] | ||
|H | |[[Half-Carry Flag|H]] | ||
|I | |[[Interrupt Enable Flag|I]] | ||
|Z | |[[Zero Flag|Z]] | ||
|C | |[[Carry Flag|C]] | ||
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'''CBNE''' is an [[SPC700]] instruction that performs a comparison between the [[accumulator]] and a [[direct page]] value and then branches if they are not equal. The direct page index is the first operand and also the first byte immediately following the opcode, and the relative branch offset is the second operand, the second byte following the opcode. | |||
=== See Also === | === See Also === | ||
* [[DBNZ]] | * [[DBNZ]] | ||
* [[BNE (SPC700)]] | |||
=== External Links === | === External Links === | ||
* Official Super Nintendo development manual on CBNE: [https://archive.org/details/SNESDevManual/book1/page/ | * Official Super Nintendo development manual on CBNE: Table C-15, [https://archive.org/details/SNESDevManual/book1/page/n233 Appendix C-8 of book I] | ||
[[Category:ASM]] | [[Category:ASM]] | ||
[[Category:SPC700]] | [[Category:SPC700]] | ||
[[Category:Branching Commands]] | [[Category:Branching Commands]] | ||
Latest revision as of 10:27, 14 December 2023
| Basic Info | |||||||
|---|---|---|---|---|---|---|---|
| Addressing Mode | Opcode | Length | Speed | ||||
| Direct Page / Program Counter Relative | 2E | 3 bytes | when condition is false: 5 cycles
when condition is true: 7 cycles |
||||
| Direct Page Indexed by X / Program Counter Relative | DE | 3 bytes | when condition is false: 6 cycles
when condition is true: 8 cycles | ||||
| Flags Affected | |||||||
|---|---|---|---|---|---|---|---|
| N | V | P | B | H | I | Z | C |
| . | . | . | . | . | . | . | . |
CBNE is an SPC700 instruction that performs a comparison between the accumulator and a direct page value and then branches if they are not equal. The direct page index is the first operand and also the first byte immediately following the opcode, and the relative branch offset is the second operand, the second byte following the opcode.
See Also
External Links
- Official Super Nintendo development manual on CBNE: Table C-15, Appendix C-8 of book I