We've just updated MediaWiki and its underlying software. If anything doesn't look or work quite right, please mention it to us. --RanAS
BBC (SPC700): Difference between revisions
From SnesLab
(improve description) |
(dp admode) |
||
| Line 7: | Line 7: | ||
|'''Speed''' | |'''Speed''' | ||
|+ | |+ | ||
| | |[[Direct Page Addressing | Direct Page]] | ||
|13 | |13 | ||
|3 byte | |3 byte | ||
| Line 13: | Line 13: | ||
when condition is true: 7 cycles | when condition is true: 7 cycles | ||
|+ | |+ | ||
| | |[[Direct Page Addressing | Direct Page]] | ||
|33 | |33 | ||
|3 byte | |3 byte | ||
| Line 19: | Line 19: | ||
when condition is true: 7 cycles | when condition is true: 7 cycles | ||
|+ | |+ | ||
| | |[[Direct Page Addressing | Direct Page]] | ||
|53 | |53 | ||
|3 byte | |3 byte | ||
| Line 25: | Line 25: | ||
when condition is true: 7 cycles | when condition is true: 7 cycles | ||
|+ | |+ | ||
| | |[[Direct Page Addressing | Direct Page]] | ||
|73 | |73 | ||
|3 byte | |3 byte | ||
| Line 31: | Line 31: | ||
when condition is true: 7 cycles | when condition is true: 7 cycles | ||
|+ | |+ | ||
| | |[[Direct Page Addressing | Direct Page]] | ||
|93 | |93 | ||
|3 byte | |3 byte | ||
| Line 37: | Line 37: | ||
when condition is true: 7 cycles | when condition is true: 7 cycles | ||
|+ | |+ | ||
| | |[[Direct Page Addressing | Direct Page]] | ||
|B3 | |B3 | ||
|3 byte | |3 byte | ||
| Line 43: | Line 43: | ||
when condition is true: 7 cycles | when condition is true: 7 cycles | ||
|+ | |+ | ||
| | |[[Direct Page Addressing | Direct Page]] | ||
|D3 | |D3 | ||
|3 byte | |3 byte | ||
| Line 49: | Line 49: | ||
when condition is true: 7 cycles | when condition is true: 7 cycles | ||
|+ | |+ | ||
| | |[[Direct Page Addressing | Direct Page]] | ||
|F3 | |F3 | ||
|3 byte | |3 byte | ||
Revision as of 17:03, 24 July 2023
| Basic Info | |||||||
|---|---|---|---|---|---|---|---|
| Addressing Mode | Opcode | Length | Speed | ||||
| Direct Page | 13 | 3 byte | when condition is false: 5 cycles
when condition is true: 7 cycles |
||||
| Direct Page | 33 | 3 byte | when condition is false: 5 cycles
when condition is true: 7 cycles |
||||
| Direct Page | 53 | 3 byte | when condition is false: 5 cycles
when condition is true: 7 cycles |
||||
| Direct Page | 73 | 3 byte | when condition is false: 5 cycles
when condition is true: 7 cycles |
||||
| Direct Page | 93 | 3 byte | when condition is false: 5 cycles
when condition is true: 7 cycles |
||||
| Direct Page | B3 | 3 byte | when condition is false: 5 cycles
when condition is true: 7 cycles |
||||
| Direct Page | D3 | 3 byte | when condition is false: 5 cycles
when condition is true: 7 cycles |
||||
| Direct Page | F3 | 3 byte | when condition is false: 5 cycles
when condition is true: 7 cycles | ||||
| Flags Clobbered | |||||||
|---|---|---|---|---|---|---|---|
| N | V | P | B | H | I | Z | C |
| . | . | . | . | . | . | . | . |
BBC (Branch on Bit Clear) is an SPC700 instruction that performs a branch when a bit in the direct page is clear. The direct page byte that bit lives in is the first operand. The bit within that byte is a function of the high nibble of the opcode. The target relative address to jump to is the second operand.
See Also
External Links
- Official Super Nintendo development manual on BBC: Appendix C-8 of Book I