ST10 FAMILY PROGRAMMING MANUAL
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JNBS
Relative Jump if Bit Clear & Set Bit
Syntax
JNBS op1,
op2
Operation
IF (op1) = 0 THEN
(op1) = 1
(IP)
<-- (IP) + sign_extend (op2)
ELSE
Next Instruction
END IF
Data Types
BIT
Description
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 sema-
phore 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 following the JNBS instruction. If the specified bit was set, the instruction following the
JNBS instruction is executed.
Flags
Addressing Modes
E
Z
V
C
N
0
B
0
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
Format
Bytes
JNBS
bitaddr
Q.q
, rel
BA QQ rr q0
4
Содержание ST10 Series
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