59
D EY
D EY
DE
CREMENT INDEX REGISTER
Y
BY ONE
(Y)
←
(Y) – 1
This instruction subtracts one from the current contents of Y.
N is 1 when bit 7 is 1 after the operation; otherwise N is
0.
No change
No change
No change
No change
No change
Z is 1 when the operation result is 0; otherwise Z is 0.
No change
Op e r a t io n :
F u n c t io n :
St a t u s fla g :
N :
V :
T :
B :
I :
D :
Z :
C :
Addressing mode
Implied
Statement
∆
DEY
Machine codes
88
16
Cycle number
2
Byte number
1