ST10 FAMILY PROGRAMMING MANUAL
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JBC
Relative Jump if Bit Set & Clear Bit
Syntax
JBC
op1, op2
Operation
IF (op1) = 1 THEN
(op1) = 0
(IP)
<-- (IP) + sign_extend (op2)
ELSE
Next Instruction
END IF
Data Types
BIT
Description
If the bit specified by op1 is set, program execution continues at the location of the instruction pointer, IP,
plus the specified displacement, op2. The bit specified by op1 is cleared, 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 following the JBC instruction. If the specified bit was clear, the instruction follow-
ing the JBC 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
JBC
bitaddr
Q.q
, rel
AA QQ rr q0
4
Содержание ST10 Series
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