8051 Instruction Set Manual

JBC

The JBC instruction branches to the address specified in the second operand if the value of the bit specified in the first operand is 1.Otherwise, execution continues with the next instruction.

If the bit specified in the first operand is set, it is cleared. No flags are affected by this instruction.

Note

When this instruction is used to modify an output port, the value used as the port data is read from the output data latch, not the input pins of the port.

See Also: JB

JBC bit, offset
CACF0RS1RS0OV P
Bytes3
Cycles2
Encoding
00010000bitoffset
Operation
JBC
PC = PC + 3
IF (bit) = 1
  (bit) = 0
  PC = PC + offset
Example
JBC 44h