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MICROPROCESSOR INSTRUCTION REFERENCE->TAS

TAS   Test and Set an Operand

Compatibility: 68000, 68010, 68020 and CPU32 families.


Test operand and set N and Z as appropriate.

Set high order bit (bit 7) of operand

Assembler Syntax:   TAS <ea>


<ea> - data alterable

Size:  Byte

Tests and sets the byte operand addressed by the effective address field.  The instruction tests the current value of the operand and sets the N and Z condition bits appropriately.


Condition Codes:

N    Set if most significant bit of operand is set
Z    Set if result zero, else cleared
V    Always cleared
C    Always cleared
X    Not affected

    

	Allowable Addressing Modes

	<ea>

	TAS	Dn
	TAS	(An)
	TAS	(An)+
	TAS	-(An)
	TAS	(d16,An)
	TAS	(d8,An,Xn)
	TAS	(bd,An,Xn) 2
	TAS	([bd,An,Xn],od) 1
	TAS	([bd,An],Xn,od) 1
	TAS	(xxx).W
	TAS	(xxx).L

1   68020 only
2   68020 and CPU32 only