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DEC: Difference between revisions

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'''DEC''' (Decrement) is a 65x instruction that decrements the value in the location specified by the operand. Except in [[accumulator addressing]], DEC takes two extra cycles when the accumulator is 16 bits wide.
'''DEC''' (Decrement) is a 65x instruction that decrements the value in the location specified by the operand.
 
===== Cycle Penalties =====
* Except in [[accumulator addressing]], DEC takes two extra cycles when the accumulator is 16 bits wide.
* In [[direct page addressing]] modes, DEC takes an extra cycle when the low byte of the [[direct page register]] is nonzero


=== See Also ===
=== See Also ===

Revision as of 05:09, 20 November 2023

Basic Info
Addressing Mode Opcode Length Speed
accumulator 3A 1 byte 2 cycles
absolute CE 3 bytes 6 cycles*
direct page C6 2 bytes 5 cycles*
absolute indexed X DE 3 bytes 7 cycles*
direct page indexed X D6 2 bytes 6 cycles*
Flags Affected
N V M X D I Z C
. . . . . .

DEC (Decrement) is a 65x instruction that decrements the value in the location specified by the operand.

Cycle Penalties

See Also

External Links

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