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
(becomes index reg select) |
(PLP can affect it) |
||
| Line 3: | Line 3: | ||
BRK and [[PHP]] set the break flag. IRQs, [[NMI]]s, and reset clear it.<sup>[1]</sup> | BRK and [[PHP]] set the break flag. IRQs, [[NMI]]s, and reset clear it.<sup>[1]</sup> | ||
In [[emulation mode]] the [[65c816]] has a break flag too.<sup>[2]</sup> But in native mode it becomes the [[Index Register Select]]. | In [[emulation mode]] the [[65c816]] has a break flag too.<sup>[2]</sup> But in native mode it becomes the [[Index Register Select]]. [[PLP]] can affect the break flag. | ||
[[Category:ASM]] | [[Category:ASM]] | ||
Revision as of 23:58, 21 July 2024
The Break Flag (B) exists on the SPC700, as bit 4 of the Program Status Word. It discerns between IRQs and BRK.
BRK and PHP set the break flag. IRQs, NMIs, and reset clear it.[1]
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.
See Also
References
- https://problemkaputt.de/fullsnes.htm#cpuregistersandflags
- Eyes & Lichty, page 422, Table 18.2. 65x Flags. https://archive.org/details/0893037893ProgrammingThe65816/page/422