LJMP (Super FX): Difference between revisions

Latest revision as of 19:55, 31 July 2024


Basic Info
Addressing Mode	Opcode	Length	ROM Speed	RAM Speed	Cache Speed
Absolute Long Implied (type 1)	3D9n	2 bytes	6 cycles	6 cycles	2 cycle


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

LJMP (Long Jump) is a Super FX instruction that performs a (possibly interbank) jump.

The low byte of the source register is loaded into the program bank register. The high byte of the source register is ignored.

According to fullsnes, the official documentation has the bank and offs operands for LJMP mixed up. ^[3]

The operand can be any general register from R₈ to R₁₃. The value of this general register is loaded into R₁₅ (the program counter).

The instruction following LJMP is already in the pipeline (the delay slot) and will be executed before the first instruction at the jump target.

The ALT0 state is restored. All cache flags are reset.

Syntax

LJMP Rn

Example

Let:

R₁ : 0001h

The following program jumps from 00:8006h to 01:0002h:

bank :addr  code
00   :8000h IWT R₁₀, #0002h
00   :8003h FROM R₁
00   :8004h LJMP R₁₀
00   :8006h NOP

External Links

Official Nintendo documentation on LJMP: 9.49 on page 2-9-69 of Book II
page 2-6-11 of Book II, lbid.
https://problemkaputt.de/fullsnes.htm#snescartgsuncpumisc

@@ Line 1: / Line 1: @@
-{| class="wikitable" style="float:right;clear:right;width:40%"
+{| class="wikitable" style="float:right;clear:right;width:50%"
 !colspan="8"|Basic Info
 |+
+|'''Addressing Mode'''
 |'''Opcode'''
 |'''Length'''
@@ Line 8: / Line 9: @@
 |'''Cache Speed'''
 |+
+|[[Absolute Long Implied]] (type 1)
 |3D9n
 |2 bytes
@@ 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
+|[[ALT1]]
-|ALT2
+|[[ALT2]]
-|O/V
+|[[O/V]]
-|S
+|[[Sign Flag|S]]
-|CY
+|[[CY]]
-|Z
+|[[Zero Flag|Z]]
 |+
 |0
@@ Line 35: / Line 37: @@
 |}
-'''LJMP''' is a [[Super FX]] instruction that performs a (possibly interbank) jump.
+'''LJMP''' (Long Jump) is a [[Super FX]] instruction that performs a (possibly interbank) jump.
-According to [[fullsnes]], the official documentation has the bank and offs operands for LJMP mixed up. [2]
+The low byte of the [[source register]] is loaded into the [[program bank register]].  The high byte of the source register is ignored.
+According to [[fullsnes]], the official documentation has the bank and offs operands for LJMP mixed up. <sup>[3]</sup>
+The operand can be any general register from R<sub>8</sub> to R<sub>13</sub>.  The value of this general register is loaded into R<sub>15</sub> (the program counter).
+The instruction following LJMP is already in the pipeline (the delay slot) and will be executed before the first instruction at the jump target.
+The [[ALT0]] state is restored.  All cache flags are reset.
+==== Syntax ====
+<pre>
+LJMP Rn
+</pre>
+=== Example ===
+Let:
+ R<sub>1</sub> : 0001h
+The following program jumps from 00:8006h to 01:0002h:
+ bank :addr  code
+   :8000h IWT R<sub>10</sub>, #0002h
+   :8003h FROM R<sub>1</sub>
+   :8004h LJMP R<sub>10</sub>
+   :8006h NOP
+=== See Also ===
+* [[JMP (Super FX)]]
+* [[JMP]]
+* [[BRA (Super FX)]]
+* [[BRA]]
+* [[ALT1]]
 === External Links ===
-# Official Nintendo documentation on LJMP: [https://archive.org/details/SNESDevManual/book2/page/n225 Page 2-9-69 of Book II]
+# Official Nintendo documentation on LJMP: 9.49 on [https://archive.org/details/SNESDevManual/book2/page/n225 page 2-9-69 of Book II]
+# [https://archive.org/details/SNESDevManual/book2/page/n133 page 2-6-11 of Book II], lbid.
 # https://problemkaputt.de/fullsnes.htm#snescartgsuncpumisc
 [[Category:ASM]]
 [[Category:Super FX]]
+[[Category:Two-byte Instructions]]
+[[Category:Instructions with Delay Slots]]