BMI (Super FX): Difference between revisions

Latest revision as of 08:34, 14 July 2024


Basic Info
Addressing Mode	Opcode	Length	ROM Speed	RAM Speed	Cache Speed
Program Counter Relative	0B??	2 bytes	6 cycles	6 cycles	2 cycles


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

BMI (Branch Minus) is a Super FX instruction that performs a conditional jump if the sign flag is set. If the sign flag is clear, control simply falls through. The instruction after BMI is already in the pipeline and will run even if the branch occurs.

No flags are affected.

Syntax

BMI e

where e can be from -128 to 127.

Example

Let the sign flag be set. This instruction jumps the program forward 5 bytes:

 BMI $+5h

External Links

Official Nintendo documentation on BMI: paragraph 9.21 on page 2-9-26 of Book II
example: page 2-9-27, lbid.

@@ 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'''
 |+
+|[[Program Counter Relative]]
 |0B??
 |2 bytes
@@ Line 24: / Line 26: @@
 |[[Sign Flag|S]]
 |[[CY]]
-|Z
+|[[Zero Flag|Z]]
 |+
 |.
@@ Line 35: / Line 37: @@
 |}
-'''BMI''' (Branch minus) is a [[Super FX]] instruction that performs a conditional jump if the [[sign flag]] is set.
+'''BMI''' (Branch Minus) is a [[Super FX]] instruction that performs a conditional jump if the [[sign flag]] is set.  If the sign flag is clear, control simply falls through.  The instruction after BMI is already in the pipeline and will run even if the branch occurs.
 No flags are affected.
+==== Syntax ====
+<pre>
+BMI e
+</pre>
+where e can be from -128 to 127.
+==== Example ====
+Let the sign flag be set.  This instruction jumps the program forward 5 bytes:
+<pre>
+ BMI $+5h
+</pre>
 === See Also ===