We've just updated MediaWiki and its underlying software. If anything doesn't look or work quite right, please mention it to us. --RanAS
Stack Relative Addressing: Difference between revisions
From SnesLab
(no long version) |
(what effective address actually is) |
||
| Line 11: | Line 11: | ||
They are all two bytes long. | They are all two bytes long. | ||
The effective addresses generated by stack relative addressing will always be in [[bank]] 0.<sup>[3]</sup> | The effective addresses generated by stack relative addressing will always be in [[bank]] 0.<sup>[3]</sup> The effective address is the sum of the [[stack pointer]] and the 8-bit operand byte. | ||
==== Syntax ==== | ==== Syntax ==== | ||
Revision as of 04:24, 24 July 2024
Stack Relative Addressing is supported by eight instructions:
- ADC (opcode 63)
- AND (opcode 23)
- CMP (opcode C3)
- EOR (opcode 43)
- LDA (opcode A3)
- ORA (opcode 03)
- SBC (opcode E3)
- STA (opcode 83)
They are all two bytes long. The effective addresses generated by stack relative addressing will always be in bank 0.[3] The effective address is the sum of the stack pointer and the 8-bit operand byte.
Syntax
LDA sr, S
There is no long version of this addressing mode.
See Also
References
- Eyes & Lichty page 418, https://archive.org/details/0893037893ProgrammingThe65816/page/418
- section 3.5.23 of 65c816 datasheet, https://westerndesigncenter.com/wdc/documentation/w65c816s.pdf
- lbid, section 3.2
- Clark, Bruce. http://www.6502.org/tutorials/65c816opcodes.html#5.20