DEC	DEC Decrement memory by one		DEC
Operation: M - 1 → M		N Z C I D V / / _ _ _ _
(Ref: 10.7)
Addressing Mode Assembly Language Form OP CODE No. Bytes No. Cycles Zero Page DEC Oper C6 2 5 Zero Page, X DEC Oper, X D6 2 6 Absolute DEC Oper CE 3 6 Absolute, X DEC Oper, X DE 3 7

DEX	DEX Decrement index X by one		DEX
Operation: X - 1 → X		N Z C I D V / / _ _ _ _
(Ref: 7.6)
Addressing Mode Assembly Language Form OP CODE No. Bytes No. Cycles Implied DEX CA 1 2

DEY	DEY Decrement index Y by one		DEY
Operation: Y - 1 → Y		N Z C I D V / / _ _ _ _
(Ref: 7.7)
Addressing Mode Assembly Language Form OP CODE No. Bytes No. Cycles Implied DEY 88 1 2