Chapter 5. INSTRUCTION
(23) IA
Naming :
Status :
Format :
Increment Accumulator
Set
Function :
A
A+1
<Comment>
Data of the accumulator is incremented by one. Results are
returned to the accumulator.
A carry is not allowed to have effect upon the status.
(24) IY
Naming :
Status :
Increment Y-Register and Status 1 on Carry
Carry to status
Format :
Function :
Y
Y + 1
ST
ST
1 (when Y = 15)
0 (when Y < 15)
<Comment>
Data of the Y-register is incremented by one and results are
returned to the Y-register.
Carry data as results is transferred to the status. When the
total is more than 15, the status is set.
(25) DA
Naming :
Status :
Decrement Accumulator and Status 1 on Borrow
Carry to status
Format :
Function :
A
A - 1
ST
ST
1(when A 1)
0 (when A = 0)
<Comment>
Data of the accumulator is decremented by one. As a result
(by addition of Fh), if a borrow is caused, the status is reset to
0 by logic. If the data is more than one, no borrow occurs
and thus the status is set to 1 .
5-12
HYNIX [ HYNIX SEMICONDUCTOR ]
