FROM (Super FX): Difference between revisions

Latest revision as of 12:48, 15 July 2024


Basic Info
Addressing Mode	Opcode	Length	ROM Speed	RAM Speed	Cache Speed
Implied (type 1)	Bn	1 byte	3 cycles	3 cycles	1 cycle


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

FROM is a Super FX register prefix instruction that specifies the source register. The exception is when the B Flag is set (i.e. a WITH instruction is executed immediately before) in which case a MOVES is executed instead with FROM acting as the source and WTIH as the destination.^[1]

No flags are affected.

Syntax

FROM Rn

Example

To set R₂ as the source register, run:

FROM R₂

Notes

^[1] The information in the developer manual is actually contradictory. The description of FROM claims the transfer happens from R_n (set by FROM) to D_reg (set by WITH) whereas that of MOVES R_n, R_n' claims to transfer from R_n' (set by WITH) to R_n (set by FROM) instead. According to fullsnes, it's the description of MOVES which is wrong.

External Links

Official Nintendo documentation on FROM: 9.34 on page 2-9-48 of Book II
Official Nintendo documentation on Register Prefixes: page 2-6-7 of Book II

@@ Line 26: / Line 26: @@
 |[[Sign Flag|S]]
 |[[CY]]
-|Z
+|[[Zero Flag|Z]]
 |+
 |.
@@ Line 37: / Line 37: @@
 |}
-'''FROM''' is a [[Super FX]] register prefix instruction that specifies the [[source register]]. The exception is when the [[B Flag]] is set (i.e. a [[WITH]] instruction is executed immediately before) in which case a [[MOVES]] is executed instead with WITH acting as the source and FROM as the destination.
+'''FROM''' is a [[Super FX]] register prefix instruction that specifies the [[source register]]. The exception is when the [[B Flag]] is set (i.e. a [[WITH]] instruction is executed immediately before) in which case a [[MOVES]] is executed instead with FROM acting as the source and WTIH as the destination.<sup>[1]</sup>
 No flags are affected.
@@ Line 54: / Line 54: @@
 * [[WITH (Super FX)]]
 * [[MOVES (Super FX)]]
+=== Notes ===
+<sup>[1]</sup> The information in the developer manual is actually contradictory. The description of FROM claims the transfer happens from R<sub>n</sub> (set by FROM) to D<sub>reg</sub> (set by WITH) whereas that of MOVES R<sub>n</sub>, R<sub>n</sub>' claims to transfer from R<sub>n</sub>' (set by WITH) to R<sub>n</sub> (set by FROM) instead. According to [[fullsnes]], it's the description of MOVES which is wrong.
 === External Links ===