Direct Page Addressing

Direct Page Addressing is an addressing mode that is supported by the 65c816 and SPC700. The effective addresses generated by it are always in bank 0.^[4]

The operand specifies which byte of the direct page to access.

Syntax

LDA dp

Supported by 24 instructions on the '816:

• ADC (opcode 65)
• SBC (opcode E5)
• EOR (opcode 45)
• ASL (opcode 06)
• LSR (opcode 46)
• INC (opcode E6)
• DEC (opcode C6)
• BIT (opcode 24)
• CMP (opcode C5)
• CPX (opcode E4)
• CPY (opcode C4)
• ORA (opcode 05)
• AND (opcode 25)
• LDA (opcode A5)
• LDX (opcode A6)
• LDY (opcode A4)
• ROL (opcode 26)
• ROR (opcode 66)
• STA (opcode 85)
• STX (opcode 86)
• STY (opcode 84)
• STZ (opcode 64)
• TRB (opcode 14)
• TSB (opcode 04)

See Also

• Zero Page Addressing
• Direct Page Indexed, X Addressing
• Direct Page Indexed, Y Addressing
• Direct Page Indirect Addressing
• Direct Page Bit Addressing

References

1. Eyes & Lichty, page 389: https://archive.org/details/0893037893ProgrammingThe65816/page/389
2. lbid, page 114: https://archive.org/details/0893037893ProgrammingThe65816/page/n140
3. section 3.5.17 of 65c816 datasheet, https://westerndesigncenter.com/wdc/documentation/w65c816s.pdf
4. lbid, section 3.3