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Negative Flag

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Revision as of 18:43, 4 August 2024 by Xetheria (talk | contribs) (mentioned BPL/BMI)
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The Negative Flag (N) exists on the 65c816 as bit 7 of the status register. Although there are no dedicated SEN or CLN instructions to set or clear it, it can be set with SEP and cleared with REP:

SEP #$80
REP #$80

These instructions also affect the negative flag (this bulleted list being 37 long):

Also, LSR always clears the negative flag.

BPL and BMI examine the negative flag to decide whether or not to branch.

See Also

Reference