We've just updated MediaWiki and its underlying software. If anything doesn't look or work quite right, please mention it to us. --RanAS
MOVW (SPC700): Difference between revisions
From SnesLab
m (removed blank line) |
(made flags affected more prominent) |
||
| (3 intermediate revisions by the same user not shown) | |||
| Line 25: | Line 25: | ||
|+ | |+ | ||
|Direction | |Direction | ||
|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]] | ||
|+ | |+ | ||
|to YA | |to YA | ||
| | |N | ||
|. | |. | ||
|. | |. | ||
| Line 41: | Line 41: | ||
|. | |. | ||
|. | |. | ||
| | |Z | ||
| | |. | ||
|+ | |+ | ||
|from YA | |from YA | ||
| Line 76: | Line 76: | ||
=== References === | === References === | ||
# Official Super Nintendo development manual on MOVW: [https://archive.org/details/SNESDevManual/book1/page/n233 Appendix C-8 of Book I] | # Official Super Nintendo development manual on MOVW: Table C-11 in [https://archive.org/details/SNESDevManual/book1/page/n233 Appendix C-8 of Book I] | ||
# [https://www.romhacking.net/documents/197 anomie's SPC700 doc] | # [https://www.romhacking.net/documents/197 anomie's SPC700 doc] | ||
| Line 82: | Line 82: | ||
[[Category:SPC700]] | [[Category:SPC700]] | ||
[[Category:16-bit Data Transmission Commands]] | [[Category:16-bit Data Transmission Commands]] | ||
[[Category:Two-byte Instructions]] | |||
Latest revision as of 14:05, 30 July 2024
| Basic Info | ||||
|---|---|---|---|---|
| Direction | Addressing Mode | Opcode | Length | Speed |
| to YA | Direct Page | BA | 2 bytes | 5 cycles |
| from YA | Direct Page | DA | 2 bytes | 4 cycles |
| Flags Affected | ||||||||
|---|---|---|---|---|---|---|---|---|
| Direction | N | V | P | B | H | I | Z | C |
| to YA | N | . | . | . | . | . | Z | . |
| from YA | . | . | . | . | . | . | . | . |
MOVW (Move Word) is an SPC700 instruction that moves a 16-bit direct page value to or from the YA register. There are no variations of MOVW that do not operate on YA. MOVW performs a read cycle on the low byte of the destination, but not the source.[2]
The operands are stored in the instruction stream in the opposite order they appear in the assembler source. In the assembler source, the operand on the right is the source and the operand on the left is the destination.
Example
From the IPL ROM,
MOVW YA, $F6 ; load the byte at direct page location $F6 into A and the byte at direct page location $F7 into Y MOVW $00, YA ; store the value in Y to direct page location $01 and the value in A to direct page location $00
See Also
References
- Official Super Nintendo development manual on MOVW: Table C-11 in Appendix C-8 of Book I
- anomie's SPC700 doc