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 2: / Line 2: @@
 !colspan="8"|Basic Info
 |+
+|'''Addressing Mode'''
 |'''Opcode'''
 |'''Length'''
@@ Line 8: / Line 9: @@
 |'''Cache Speed'''
 |+
+|[[Implied]] (type 1)
 |Bn
 |1 byte
@@ Line 16: / Line 18: @@
 {| class="wikitable" style="float:right;clear:right;width:30%"
-!colspan="9"|Flags Clobbered
+!colspan="9"|Flags Affected
 |+
-|B
+|[[B Flag|B]]
 |[[ALT1]]
 |[[ALT2]]
 |[[O/V]]
-|S
+|[[Sign Flag|S]]
 |[[CY]]
-|Z
+|[[Zero Flag|Z]]
 |+
 |.
@@ Line 35: / Line 37: @@
 |}
-'''FROM''' is a [[Super FX]] register prefix instruction that specifies the [[source register]].
+'''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.
+==== Syntax ====
+<pre>
+FROM Rn
+</pre>
+==== Example ====
+To set R<sub>2</sub> as the source register, run:
+ FROM R<sub>2</sub>
 === See Also ===
-* [[TO]]
+* [[TO (Super FX)]]
-* [[WITH]]
+* [[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 ===
-* Official Nintendo documentation on FROM: [https://archive.org/details/SNESDevManual/book2/page/n204 Page 2-9-48 of Book II]
+* Official Nintendo documentation on FROM: 9.34 on [https://archive.org/details/SNESDevManual/book2/page/n204 page 2-9-48 of Book II]
+* Official Nintendo documentation on Register Prefixes: [https://archive.org/details/SNESDevManual/book2/page/n129 page 2-6-7 of Book II]
 [[Category:ASM]]
 [[Category:Super FX]]
 [[Category:Register Prefix Instructions]]
+[[Category:One-byte Instructions]]