Semiconductor Group
4-33
1998-04-01
Instruction Set
C500 Family
INC
<byte>
Function:
Increment
Description:
INC increments the indicated variable by 1. An original value of 0FFH will overflow
to 00H. No flags are affected. Three addressing modes are allowed: register, direct,
or register-indirect.
Note:
When this instruction is used to modify an output port, the value used as the original
port data will be read from the output data latch,
not
the input pins.
Example:
Register 0 contains 7EH (01111110B). Internal RAM locations 7EH and 7FH
contain 0FFH and 40H, respectively. The instruction sequence
INC
@R0
INC
R0
INC
@R0
will leave register 0 set to 7FH and internal RAM locations 7EH and 7FH holding
(respectively) 00H and 41H.
INC
A
Operation:
INC
(A)
¬
(A) + 1
Bytes:
1
Cycles:
1
INC
Rn
Operation:
INC
(Rn)
¬
(Rn) + 1
Bytes:
1
Cycles:
1
Encoding:
0 0 0 0
0 1 0 0
Encoding:
0 0 0 0
1 r r r