Semiconductor Group
4-41
1998-04-01
Instruction Set
C500 Family
JNC
rel
Function:
Jump if carry is not set
Description:
If the carry flag is a zero, branch to the address indicated; otherwise proceed with
the next instruction. The branch destination is computed by adding the signed
relative-displacement in the second instruction byte to the PC, after incrementing
the PC twice to point to the next instruction. The carry flag is not modified.
Example:
The carry flag is set. The instruction sequence
JNC
LABEL1
CPL
C
JNC
LABEL2
will clear the carry and cause program execution to continue at the instruction
identified by the label LABEL2.
Operation:
JNC
(PC)
¬
(PC) + 2
if (C) = 0
then (PC)
¬
(PC) + rel
Bytes:
2
Cycles:
2
Encoding:
0 1 0 1
0 0 0 0
rel. address