We've just updated MediaWiki and its underlying software. If anything doesn't look or work quite right, please mention it to us. --RanAS

Immediate Addressing

From SnesLab
Revision as of 03:19, 9 August 2024 by Xetheria (talk | contribs) (added ref)
Jump to: navigation, search

Immediate Addressing is when the data to be operated on directly follows the opcode in the instruction steam. The immediate data is generally preceded by a # in the assembler source.[7]

Supported by the following 65c816 instructions:

  • ADC (opcode 69)
  • SBC (opcode E9)
  • EOR (opcode 49)
  • AND (opcode 29)
  • ORA (opcode 09)
  • LDA (opcode A9)
  • LDX (opcode A2)
  • LDY (opcode A0)
  • CMP (opcode C9)
  • CPX (opcode E0)
  • CPY (opcode C0)
  • BIT (opcode 89)
  • SEP (opcode E2)
  • REP (opcode C2)

They are all either 2 or 3 bytes long.

The Super FX supports immediate addressing too:

On the SPC700, "imm" means "8-bit immediate data."[4] These commands support immediate data:

Syntax

LDA #const

See Also

References

  1. Eyes & Lichty, page 397
  2. lbid, page 108
  3. Labiak, page 209
  4. Appendix C-1 of Book I of the official Super Nintendo development manual
  5. section 3.5.18 of 65c816 datasheet, https://westerndesigncenter.com/wdc/documentation/w65c816s.pdf
  6. Clark, Bruce. http://www.6502.org/tutorials/65c816opcodes.html#5.14
  7. B-2