Siemens C500 User Manual page 67

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
CPL
JNC
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
Encoding: 0 1 0 1
Bytes: 2
Cycles: 2
Semiconductor Group
LABEL1
C
LABEL2
0 0 0 0 rel. address
4-41
Instruction Set
C500 Family
1998-04-01