We've just updated MediaWiki and its underlying software. If anything doesn't look or work quite right, please mention it to us. --RanAS

Break Flag: Difference between revisions

From SnesLab
Jump to: navigation, search
(condition codes category)
(→‎References: another e&l ref)
Line 16: Line 16:
# [[Eyes & Lichty]], [https://archive.org/details/0893037893ProgrammingThe65816/page/422 page 422], Table 18.2. 65x Flags.
# [[Eyes & Lichty]], [https://archive.org/details/0893037893ProgrammingThe65816/page/422 page 422], Table 18.2. 65x Flags.
# [https://archive.org/details/0893037893ProgrammingThe65816/page/486 page 486], lbid.
# [https://archive.org/details/0893037893ProgrammingThe65816/page/486 page 486], lbid.
# [https://archive.org/details/0893037893ProgrammingThe65816/page/436 page 436] on BRK, lbid.


[[Category:ASM]]
[[Category:ASM]]

Revision as of 22:20, 21 August 2024

Note: This page may be confusing or inaccurate. See the talk page.

The Break Flag (B) is bit 4 of the S-SMP's program status word. It discerns between IRQs and BRK.

BRK and PHP[dubious] set the break flag. IRQs, NMIs, and reset clear it.[1]

RETI and POP can modify the break flag.

In emulation mode the 65c816 has a break flag too.[2] But in native mode it becomes the Index Register Select. PLP can affect the break flag.[3]

See Also

References

  1. https://problemkaputt.de/fullsnes.htm#cpuregistersandflags
  2. Eyes & Lichty, page 422, Table 18.2. 65x Flags.
  3. page 486, lbid.
  4. page 436 on BRK, lbid.