Direct Page Immediate: Difference between revisions

Latest revision as of 20:30, 12 July 2024

Some SPC700 opcodes use both Direct Page and Immediate addressing.

As it appears in assembler source, the left operand is an index into the direct page, and the right operand is an immediate value.

The following opcodes support direct page immediate addressing:

ADC (SPC700) (opcode 98h)
AND (SPC700) (opcode 38h)
SBC (SPC700) (opcode B8h)
OR (SPC700) (opcode 18h)
EOR (SPC700) (opcode 58h)
CMP (SPC700) (opcode 78h)
MOV (opcode 8Fh)

ADC dp, #imm
AND dp, #imm
SBC dp, #imm
OR dp, #imm
EOR dp, #imm
CMP dp, #imm
MOV dp, #imm

Figure 3-8-3 Memory Access Addressing Effective Address on page 3-8-9 of Book I of the official Super Nintendo development manual

@@ Line 6: / Line 6: @@
 The following opcodes support direct page immediate addressing:
-* [[ADC]] (opcode 98h)
+* [[ADC (SPC700)]] (opcode 98h)
-* [[AND]] (opcode 38h)
+* [[AND (SPC700)]] (opcode 38h)
-* [[SBC]] (opcode B8h)
+* [[SBC (SPC700)]] (opcode B8h)
-* [[OR]] (opcode 18h)
+* [[OR (SPC700)]] (opcode 18h)
-* [[EOR]] (opcode 58h)
+* [[EOR (SPC700)]] (opcode 58h)
-* [[CMP]] (opcode 78h)
+* [[CMP (SPC700)]] (opcode 78h)
 * [[MOV]] (opcode 8Fh)
+==== Syntax ====
+<pre>
+ADC dp, #imm
+AND dp, #imm
+SBC dp, #imm
+OR dp, #imm
+EOR dp, #imm
+CMP dp, #imm
+MOV dp, #imm
+</pre>
+=== See Also ===
+* [[Direct Page Addressing]]
+* [[Direct Page Bit Addressing]]
+* [[Direct Page Bit Relative Addressing]]
+=== Reference ===
+* Figure 3-8-3 Memory Access Addressing Effective Address on [https://archive.org/details/SNESDevManual/book1/page/n187 page 3-8-9 of Book I] of the official Super Nintendo development manual
 [[Category:ASM]]