BVC: Difference between revisions

Latest revision as of 11:45, 14 December 2023


Basic Info
Addressing Mode	Opcode	Length	Speed
Program Counter Relative	50	2 bytes	2 cycles*


Flags Affected
N	V	M	X	D	I	Z	C
.	.	.	.	.	.	.	.

BVC is a 65x instruction that performs a branch if the overflow flag is clear.

Cycle Penalties

BVC takes one extra cycle if the branch is taken
BVC takes another extra cycle if that branch taken crosses a page boundary in emulation mode.

External Links

Eyes & Lichty page 439 on BVC: https://archive.org/details/0893037893ProgrammingThe65816/page/n465
Labiak page 128 on BVC: https://archive.org/details/Programming_the_65816/page/n138
MCS6500 Manual page 41 on BVC: https://archive.org/details/mos_microcomputers_programming_manual/page/n56
Carr page 252 on BVC: https://archive.org/details/6502UsersManual/page/n265
Leventhal page 3-51 on BVC: https://archive.org/details/6502-assembly-language-programming/page/n100
snes9x implementation of BVC: https://github.com/snes9xgit/snes9x/blob/master/cpuops.cpp#L1395

@@ Line 1: / Line 1: @@
-'''BVC''' is a 65x instruction that performs a branch if the [[overflow flag]] is clear.
+{| class="wikitable" style="float:right;clear:right;width:40%"
-{| class="wikitable" style="float:right;clear:right;width:30%"
 !colspan="8"|Basic Info
 |+
@@ Line 9: / Line 7: @@
 |'''Speed'''
 |+
-|relative
+|[[Program Counter Relative]]
 |50
-|2 byte
+|2 bytes
-|2 cycles
+|2 cycles*
 |}
 {| class="wikitable" style="float:right;clear:right;width:30%"
-!colspan="9"|Flags Clobbered
+!colspan="9"|Flags Affected
 |+
-|N
+|[[Negative Flag|N]]
-|V
+|[[Overflow Flag|V]]
-|M
+|[[M Flag|M]]
-|X
+|[[X Flag|X]]
-|D
+|[[Decimal Flag|D]]
-|I
+|[[I Flag|I]]
-|Z
+|[[Zero Flag|Z]]
-|C
+|[[Carry Flag|C]]
 |+
 |.
@@ Line 36: / Line 34: @@
 |.
 |}
+'''BVC''' is a 65x instruction that performs a branch if the [[overflow flag]] is clear.
+===== Cycle Penalties =====
+* BVC takes one extra cycle if the branch is taken
+* BVC takes another extra cycle if that branch taken crosses a page boundary in [[emulation mode]].
+=== See Also ===
+* [[BVS]]
+* [[BVC (SPC700)]]
 === External Links ===
-* [[Eyes & Lichty]] page on BVC: https://archive.org/details/0893037893ProgrammingThe65816/page/n465
+* [[Eyes & Lichty]] page 439 on BVC: https://archive.org/details/0893037893ProgrammingThe65816/page/n465
-* [[Labiak]] page on BVC: https://archive.org/details/Programming_the_65816/page/n138
+* [[Labiak]] page 128 on BVC: https://archive.org/details/Programming_the_65816/page/n138
-* [[MCS6500 Manual]] page on BVC: https://archive.org/details/mos_microcomputers_programming_manual/page/n56
+* [[MCS6500 Manual]] page 41 on BVC: https://archive.org/details/mos_microcomputers_programming_manual/page/n56
-* [[Carr]] page on BVC: https://archive.org/details/6502UsersManual/page/n265
+* [[Carr]] page 252 on BVC: https://archive.org/details/6502UsersManual/page/n265
-* [[Leventhal]] page on BVC: https://archive.org/details/6502-assembly-language-programming/page/n100
+* [[Leventhal]] page 3-51 on BVC: https://archive.org/details/6502-assembly-language-programming/page/n100
 * snes9x implementation of BVC: https://github.com/snes9xgit/snes9x/blob/master/cpuops.cpp#L1395
 [[Category:ASM]]
 [[Category:Inherited from 6502]]
+[[Category:Conditional Branches]]
+[[Category:Two-byte Instructions]]
+[[Category:Two-cycle Instructions]]