IWT (Super FX): Difference between revisions

Latest revision as of 01:55, 16 July 2024


Basic Info
Addressing Mode	Opcode	Length	ROM Speed	RAM Speed	Cache Speed
Immediate	Fnxxxx	3 bytes	9 cycles	9 cycles	3 cycle


Flags Affected
B	ALT1	ALT2	O/V	S	CY	Z
0	0	0	.	.	.	.

IWT (Immediate Word Transfer) is a Super FX instruction that loads two immediate bytes into a register. Any register from R₀ to R₁₅ may be specified.

The ALT0 state is restored.

Syntax

IWT Rn, #xx

Example

When:

IWT R₀, #4583h

is executed:

R₀ = 4583h

Trivia

The official Super Nintendo development manual mispells the mnemonic as "ITW" in the opcode diagram.^[1] The low byte of the immediate value is loaded before the high byte.

External Links

Official Nintendo documentation on IWT: 9.43 on Page 2-9-62 of Book II

@@ Line 26: / Line 26: @@
 |[[Sign Flag|S]]
 |[[CY]]
-|Z
+|[[Zero Flag|Z]]
 |+
 |0
@@ Line 37: / Line 37: @@
 |}
-'''IWT''' (Immediate Word Data?) is a [[Super FX]] instruction that loads two immediate bytes into a register.  Any register from R<sub>0</sub> to R<sub>15</sub> may be specified.
+'''IWT''' (Immediate Word Transfer) is a [[Super FX]] instruction that loads two immediate bytes into a register.  Any register from R<sub>0</sub> to R<sub>15</sub> may be specified.
+The [[ALT0]] state is restored.
 ==== Syntax ====
@@ Line 43: / Line 45: @@
 IWT Rn, #xx
 </pre>
+==== Example ====
+When:
+ IWT R<sub>0</sub>, #4583h
+is executed:
+ R<sub>0</sub> = 4583h
 === Trivia ===
@@ Line 50: / Line 58: @@
 * [[IBT]]
 * [[LDA]]
+* [[LDX]]
+* [[LDY]]
 * [[LEA]]