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BLT (Super FX): Difference between revisions

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'''BLT''' (Branch if Less Than ) is a [[Super FX]] opcode that performs a jump if the [[negative flag]] is unequal to the [[O/V]] flag, effectively checking for a signed less-than comparison (compare [[BCC]] which is an unsigned less-than comparison).
{| class="wikitable" style="float:right;clear:right;width:50%"
 
According to [[fullsnes]], the official documentation has BLT exchanged with [[BGE]]. [2]
 
{| class="wikitable" style="float:right;clear:right;width:40%"
!colspan="8"|Basic Info
!colspan="8"|Basic Info
|+
|+
|'''Addressing Mode'''
|'''Opcode'''
|'''Opcode'''
|'''Length'''
|'''Length'''
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|'''Cache Speed'''
|'''Cache Speed'''
|+
|+
|[[Program Counter Relative]]
|06
|06
|2 bytes
|2 bytes
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{| class="wikitable" style="float:right;clear:right;width:30%"
{| 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
|.
|0
|.
|0
|.
|.
|.
|.
|.
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|.
|.
|}
|}
'''BLT''' (Branch if Less Than) is a [[Super FX]] opcode that performs a jump if the [[sign flag]] is unequal to the [[O/V]] flag, effectively checking for a signed less-than comparison (compare [[BCC]] which is an unsigned less-than comparison).
According to [[fullsnes]], the official documentation has BLT exchanged with [[BGE]]. <sup>[2]</sup>
No flags are affected.
==== Syntax ====
<pre>
BLT e
</pre>
==== Example ====
Let the sign flag be set and the overflow flag clear.  This instruction jumps the program forward 4 bytes:
<pre>
BLT $+4h
</pre>


=== See also ===
=== See also ===
* [[BGE]]
* [[BGE]]
* [[BCC]]
* [[BCC (Super FX)]]


=== External Links ===
=== External Links ===
* Official Nintendo documentation on BLT: [https://archive.org/details/SNESDevManual/book2/page/n180 Page 2-9-24 of Book II]
# Official Nintendo documentation on BLT: [https://archive.org/details/SNESDevManual/book2/page/n180 Page 2-9-24 of Book II]
* [2] https://problemkaputt.de/fullsnes.htm#snescartgsuncpumisc
# https://problemkaputt.de/fullsnes.htm#snescartgsuncpumisc
# example: [https://archive.org/details/SNESDevManual/book2/page/n181 page 2-9-25], lbid.


[[Category:ASM]]
[[Category:ASM]]
[[Category:Super FX]]
[[Category:Super FX]]
[[Category:GSU Control Instructions]]
[[Category:GSU Control Instructions]]
[[Category:Instructions with Delay Slots]]

Latest revision as of 19:16, 4 August 2024

Basic Info
Addressing Mode Opcode Length ROM Speed RAM Speed Cache Speed
Program Counter Relative 06 2 bytes 6 cycles 6 cycles 2 cycles
Flags Affected
B ALT1 ALT2 O/V S CY Z
. . . . . . .

BLT (Branch if Less Than) is a Super FX opcode that performs a jump if the sign flag is unequal to the O/V flag, effectively checking for a signed less-than comparison (compare BCC which is an unsigned less-than comparison).

According to fullsnes, the official documentation has BLT exchanged with BGE. [2]

No flags are affected.

Syntax

BLT e

Example

Let the sign flag be set and the overflow flag clear. This instruction jumps the program forward 4 bytes:

 BLT $+4h

See also

External Links

  1. Official Nintendo documentation on BLT: Page 2-9-24 of Book II
  2. https://problemkaputt.de/fullsnes.htm#snescartgsuncpumisc
  3. example: page 2-9-25, lbid.