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Program Counter

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The Program Counter (PC) keeps track of which instruction is currently executing. On both the 65c816 and S-SMP it is 16 bits wide. The low byte is called PCL and the high byte is called PCH.

If incremented past FFFFh, it wraps around to zero.[E&L, page 34]

The 6502 had 16-bit absolute addressing but only an 8-bit adder, so in emulation mode branches that cross a page boundary incur a one cycle penalty. 65c816 native mode has no such penalty because the full 16-bit adder is used.

See Also

References