ASL (SPC700): Difference between revisions

Latest revision as of 00:05, 15 August 2024


Basic Info
Addressing Mode	Opcode	Length	Speed
Accumulator	1C	1 byte	2 cycles
Direct Page	0B	2 bytes	4 cycles
Direct Page Indexed by X	1B	2 bytes	5 cycles
Absolute	0C	3 bytes	5 cycles


Flags Affected
N	V	P	B	H	I	Z	C
N	.	.	.	.	.	Z	C

ASL (Arithmetic Shift Left) is an SPC700 instruction that shifts all 8 bits of its operand one bit to the left, more or less multiplying it by two. A zero is shifted into the least significant bit. The most significant bit is shifted into the carry flag.

Syntax

ASL A
ASL dp
ASL dp+x
ASL !abs

External Links

Official Super Nintendo development manual on ASL: Appendix C-7 of Book I
anomie: https://github.com/yupferris/TasmShiz/blob/master/spc700.txt#L335

@@ Line 40: / Line 40: @@
 |[[Carry Flag|C]]
 |+
-|
+|N
 |.
 |.
@@ Line 46: / Line 46: @@
 |.
 |.
-|
+|Z
-|
+|C
 |}
-'''ASL''' (Arithmetic Shift Left) is an [[SPC700]] instruction that shifts its operand one bit to the left, more or less multiplying it by two.  A zero is shifted into the least significant bit.  The most significant bit is shifted into the [[carry flag]].
+'''ASL''' (Arithmetic Shift Left) is an [[SPC700]] instruction that shifts all 8 bits of its operand one bit to the left, more or less multiplying it by two.  A zero is shifted into the least significant bit.  The most significant bit is shifted into the [[carry flag]].
 ==== Syntax ====
@@ Line 59: / Line 59: @@
 ASL !abs
 </pre>
+[[File:asl_spc.png]]
 === See Also ===