68000 Instruction Set

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Instruction	Description	Assembler Syntax	Data Size	Condition Codes X N Z V C
ABCD	Add BCD with Extend	Dx,Dy -(Ax),-(Ay)	B--	* U * U *
ADD	ADD binary	Dn,< ea > < ea >,Dn	BWL	* * * * *
ADDA	ADD binary to An	< ea >,An	-WL	- - - - -
ADDI	Add Immediate	#x,< ea >	BWL	* * * * *
ADDQ	ADD 3-bit immediate	#<1-8>,< ea >	BWL	* * * * *
ADDX	ADD eXtended	Dy,Dx -(Ay),-(Ax)	BWL	* * * * *
AND	Bit-wise AND	< ea >,Dn Dn,< ea >	BWL	- * * 0 0
ANDI	Bit-wise AND with Immediate	#< data>,< ea >	BWL	- * * 0 0
ASL	Arithmetic Shift Left	#<1-8>,Dy Dx,Dy < ea >	BWL	* * * * *
ASR	Arithmetic Shift Right		BWL	* * * * *
Bcc	Conditional Branch	Bcc.S < label> Bcc.W < label>	BW-	- - - - -
BCHG	Test a Bit and ChanGe	Dn,< ea > #< data>,< ea >	B-L	- - * - -
BCLR	Test a Bit and CLEAR		B-L	- - * - -
BSET	Test a Bit and SET		B-L	- - * - -
BSR	Branch to SubRoutine	BSR.S < label> BSR.W < label>	BW-	- - - - -
BTST	Bit TeST	Dn,< ea > #< data>,< ea >	B-L	- - * - -
CHK	CHecK Dn Against Bounds	< ea >,Dn	-W-	- * U U U
CLR	CLEAR	< ea >	BWL	- 0 1 0 0
CMP	CoMPare	< ea >,Dn	BWL	- * * * *
CMPA	CoMPare Address	< ea >,An	-WL	- * * * *
CMPI	CoMPare Immediate	#< data>,< ea >	BWL	- * * * *
CMPM	CoMPare Memory	(Ay)+,(Ax)+	BWL	- * * * *
DBcc	Looping Instruction	DBcc Dn,< label>	-W-	- - - - -
DIVS	DIVide Signed	< ea >,Dn	-W-	- * * * 0
DIVU	DIVide Unsigned	< ea >,Dn	-W-	- * * * 0
EOR	Exclusive OR	Dn,< ea >	BWL	- * * 0 0
EORI	Exclusive OR Immediate	#< data>,< ea >	BWL	- * * 0 0
EXG	Exchange any two registers	Rx,Ry	--L	- - - - -
EXT	Sign EXTend	Dn	-WL	- * * 0 0
ILLEGAL	ILLEGAl-Instruction Exception	ILLEGAL		- - - - -
JMP	JuMP to Affective Address	< ea >		- - - - -
JSR	Jump to SubRoutine	< ea >		- - - - -
LEA	Load Effective Address	< ea >,An	--L	- - - - -
LINK	Allocate Stack Frame	An,#< displacement>		- - - - -
LSL	Logical Shift Left	Dx,Dy #<1-8>,Dy < ea >	BWL	* * * 0 *
LSR	Logical Shift Right		BWL	* * * 0 *
MOVE	Between Effective Addresses	< ea >,< ea >	BWL	- * * 0 0
MOVE	To CCR	< ea>,CCR	-W-	I I I I I
MOVE	To SR	< ea >,SR	-W-	I I I I I
MOVE	From SR	SR,< ea >	-W-	- - - - -
MOVE	USP to/from Address Register	USP,An An,USP	--L	- - - - -
MOVEA	MOVE Address	< ea >,An	-WL	- - - - -
MOVEM	MOVE Multiple	<register list>,< ea > < ea >,<register list>	-WL	- - - - -
MOVEP	Move Peripheral	Dn,x(An) x(An),Dn	-WL	- - - - -
MOVEQ	Move 8-bit immediate	#<-128.+127>,Dn	--L	- * * 0 0
MULS	MULtiply Signed	< ea >,Dn	-W-	- * * 0 0
MULU	MULtiply Unsigned	< ea >,Dn	-W-	- * * 0 0
NBCD	Negate BCD	< ea >	B--	* U * U *
NEG	NEGate	< ea >	BWL	* * * * *
NEGX	NEGate with eXtend	< ea >	BWL	* * * * *
NOP	No OPeration	NOP		- - - - -
NOT	Form one's complement	< ea >	BWL	- * * 0 0
OR	Bit-wise OR	< ea >,Dn Dn,< ea >	BWL	- * * 0 0
ORI	Bit-wise OR with Immediate	#< data>,< ea >	BWL	- * * 0 0
PEA	Push Effective Address	< ea >	--L	- - - - -
RESET	RESET all external devices	RESET		- - - - -
ROL	ROtate Left	#<1-8>,Dy Dx,Dy < ea >	BWL	- * * 0 *
ROR	ROtate Right		BWL	- * * 0 *
ROXL	ROtate Left with eXtend		BWL	* * * 0 *
ROXR	ROtate Right with eXtend		BWL	* * * 0 *
RTE	ReTurn from Exception	RTE		I I I I I
RTR	ReTurn and Restore	RTR		I I I I I
RTS	ReTurn from Subroutine	RTS		- - - - -
SBCD	Subtract BCD with eXtend	Dx,Dy -(Ax),-(Ay)	B--	* U * U *
Scc	Set to -1 if True, 0 if False	< ea >	B--	- - - - -
STOP	Enable & wait for interrupts	#< data>		I I I I I
SUB	SUBtract binary	Dn,< ea > < ea >,Dn	BWL	* * * * *
SUBA	SUBtract binary from An	< ea >,An	-WL	- - - - -
SUBI	SUBtract Immediate	#x,< ea >	BWL	* * * * *
SUBQ	SUBtract 3-bit immediate	#< data>,< ea >	BWL	* * * * *
SUBX	SUBtract eXtended	Dy,Dx -(Ay),-(Ax)	BWL	* * * * *
SWAP	SWAP words of Dn	Dn	-W-	- * * 0 0
TAS	Test & Set MSB & Set N/Z-bits	< ea >	B--	- * * 0 0
TRAP	Execute TRAP Exception	#< vector>		- - - - -
TRAPV	TRAPV Exception if V-bit Set	TRAPV		- - - - -
TST	TeST for negative or zero	< ea >	BWL	- * * 0 0
UNLK	Deallocate Stack Frame	An		- - - - -

Legend

• * - Set according to result of operation
• - - Not affected
• 0 - Cleared
• 1 - Set
• U - Outcome (state after operation) undefined
• I - Set by immediate data
• < ea > - Effective Address Operand
• < data> - Immediate data
• < label> - Assembler label
• < vector> TRAP instruction Exception vector (0-15)
• < rg.lst> MOVEM instruction register specification list
• < displ.> LINK instruction negative displacement

Addressing Modes	Syntax
Data Register Direct	Dn
Address Register Direct	An
Address Register Indirect	(An)
Address Register Indirect with Post-Increment	(An)+
Address Register Indirect with Pre-Decrement	-(An)
Address Register Indirect with Displacement	w(An)
Address Register Indirect with Index	b(An,Rx)
Absolute Short	w
Absolute Long	l
Program Counter with Displacement	w(PC)
Program Counter with Index	b(PC,Rx)
Immediate	#x
Status Register	SR
Condition Code Register	CCR

Legend

• Dn - Data Register (n is 0-7)
• An - Address Register (n is 0-7)
• b - 08-bit constant
• w - 16-bit constant
• l - 32-bit constant
• x - 8-, 16-, 32-bit constant
• Rx - Index Register Specification, one of:
• Dn.W - Low 16 bits of Data Register
• Dn.L - All 32 bits of Data Register
• An.W - Low 16 bits of Address Register
• An.L - All 32 bits of Address Register

Condition Codes for Bcc, DBcc and Scc Instructions

Condition Codes set after CMP D0,D1 Instruction.

Relationship	Unsigned	Signed
D1 < D0	CS - Carry Bit Set/LO - LOwer	LT - Less Than
D1 <= D0	LS - Lower or Same	LE - Less than or Equal
D1 = D0	EQ - Equal (Z-bit Set)
D1 != D0	NE - Not Equal (Z-bit Clear)
D1 > D0	HI - HIgher than	GT - Greater Than
D1 >= D0	CC - Carry Bit Clear/HS - Higher or Same	GE - Greater than or Equal
D0 >= 0	PL - PLus (N-bit Clear)
D0 < 0	MI - MInus (N-bit Set)
	VC - V-bit Clear (No Overflow)
	VS - V-bit Set (Overflow)
Bcc only
	RA - BRanch Always
DBcc only
	F - Never Terminate (DBRA is an alternate to DBF)
	T - Always Terminate
Scc only
	SF - Never Set
	ST - Always Set