Dec mn dec sp – Epson S1C6200 User Manual
Page 44
Source Format:
Operation:
OP-Code:
Type:
Clock Cycles:
Flag:
Description:
Example:
Source Format:
Operation:
OP-Code:
Type:
Clock Cycles:
Flag:
Description:
Example:
MSB
LSB
MSB
LSB
C –
Z –
D –
I –
C –
Z –
D –
I –
38
EPSON
S1C6200/6200A CORE CPU MANUAL
3 INSTRUCTION SET
DEC Mn
DEC SP
Decrement stack pointer
Decrement memory
DEC Mn
M(n
3
to n
0
)
←
M(n
3
to n
0
) - 1
1
1
1
1
0
1
1
1 n
3
n
2
n
1
n
0
F70H to F7FH
IV
7
Set if a borrow is generated; otherwise, reset.
Set if the result is zero; otherwise, reset.
Not affected
Not affected
Decrements the contents of the data memory location addressed by Mn by 1.
DEC M0
DEC M2
DEC M0FH
Memory (00H)
1001
1000
1000
1000
Memory (02H)
0000
0000
1111
1111
Memory (0FH)
0001
0001
0001
0000
C flag
1
0
1
0
Z flag
0
0
0
1
DEC SP
SP
←
SP - 1
1
1
1
1
1
1
0
0
1
0
1
1
FCBH
VI
5
Not affected
Not affected
Not affected
Not affected
Decrements the contents of the stack pointer by 1. This operation does not affect
the flags.
DEC SP
Memory (SP)
1011 0001
1011 0000
C flag
0
0
Z flag
1
1