Siemens C16 Series Instruction Set Manual page 81

JNBS
Syntax
Operation
Data Types
Description
Condition Flags
Addressing Modes
Semiconductor Group
30Mar98@15:00h
Relative Jump if Bit Clear and Set Bit
JNBS op1, op2
IF (op1) = 0 THEN
(op1) = 1
(IP) ← (IP) + sign_extend (op2)
ELSE
Next Instruction
END IF
BIT
If the bit specified by op1 is clear, program execution continues at the
location of the instruction pointer, IP, plus the specified displacement, op2.
The bit specified by op1 is set, allowing implementation of semaphore
operations. The displacement is a two's complement number which is sign
extended and counts the relative distance in words. The value of the IP
used in the target address calculation is the address of the instruction fol-
lowing the JNBS instruction. If the specified bit was set, the instruction fol-
lowing the JNBS instruction is executed.
E Z
0 B
E Always cleared.
Z Contains logical negation of the previous state of the specified bit.
V Always cleared.
C Always cleared.
N Contains the previous state of the specified bit.
Mnemonic
JNBS bitaddr
Q.q
C166 Family Instruction Set
V C N
0 0 B
Format
, rel BA QQ rr q0
81
Instruction Description
JNBS
Version 1.2, 12.97
Bytes
4