Function:

Basically copies bit(op2) from op1 into CY and complements bit(op2) of op1.
Memory variant is more complex. Do not use on memory mapped I/O ports or
memory operands that span into or lie completely within nonexistent memory.
In the case of memory mapped I/O ports, use MOV and TEST instead.




BTR op1,op2   Bit Test and Reset
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