Immediate Addressing

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.

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:

• ADC
• ADD
• AND
• BIC
• SUB
• OR
• MULT
• IWT
• IBT
• LINK
• and presumably UMULT too

On the SPC700, "imm" means "8-bit immediate data."^[4]

Syntax

LDA #const

See Also

• Implied Addressing
• Accumulator Addressing
• PEA

Reference

1. Eyes & Lichty page 397, https://archive.org/details/0893037893ProgrammingThe65816/page/397
2. lbid, page 108: https://archive.org/details/0893037893ProgrammingThe65816/page/108
3. Labiak page 209: https://archive.org/details/Programming_the_65816/page/n219
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