Siemens C500 User Manual page 69

JZ rel
Function: Jump if accumulator is zero
Description: If all bits of the accumulator are 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. The accumulator is not modified. No flags are affected.
Example: The accumulator originally contains 01 H . The instruction sequence
JZ
DEC
JZ
will change the accumulator to 00 H and cause program execution to continue at the
instruction identified by the label LABEL2.
Operation: JZ
(PC) ¬ (PC) + 2
if (A) = 0
then (PC) ¬ (PC) + rel
Encoding: 0 1 1 0
Bytes: 2
Cycles: 2
Semiconductor Group
LABEL1
A
LABEL2
0 0 0 0 rel. address
4-43
Instruction Set
C500 Family
1998-04-01