Table of Contents        Previous topic       Next topic       

MICROPROCESSOR INSTRUCTION REFERENCE->BCHG

BCHG    Test a Bit and Change

Complement of (<bit no.> Destination) -> Z
Complement of (<bit no.> Destination) -> (<bit no.> Destination)
    

Assembler Syntax:	BCHG Dn,<ea>
	BCHG #<data>,<ea>

Dn or #<data> specify the bit number

Size:  Byte, Long

Tests a bit in the destination operand and sets the Z condition code appropriately, then inverts the specified bit in the destination.  When the destination is a data register, any of the 32 bits can be specified by the modulo 32-bit number.  When the destination is a memory location, the operation is a byte operation, and the bit number is modulo 8.  In all cases, bit zero refers to the least significant bit.

If <ea> is Data register then #<data> 0 - 31 else #<data> 0 - 7

Condition Codes:

N    Not affected
Z    Set if bit tested = 0, else clear
V    Not affected
C    Not affected
X    Not affected

    

	Allowable Addressing Modes

	Dn,<ea>		#<data>,<ea>

	Dn,Dn	#(data),Dn
	Dn,(An)	#(data),(An)
	Dn,(An)+	#(data),(An)+
	Dn,-(An)	#(data),-(An)
	Dn,(d16,An)	#(data),(d16,An)
	Dn,(d8,An,Xn)
	Dn,(xxx).W
	Dn,(xxx).L

Dn,Dn and #(data),Dn are long only; all others are byte only.