High Level Assembler - Opcodes overview

The tables below list all documented opcodes for IBM mainframe processors. Each opcode links to a text section with some additional info on the pertinent opcode.

Special thanks:
to David Bond for his instruction lists and tables.
To Jan Jaeger for his list of instructions not listed in IBM's Principles of Operation.
And to Tom Harper for his willingness to share the results of his research on IBM patents relating to z/Architecture instructions.

Opcode Assignments.

Remark:
Please note that the creation of descriptions for all individual instructions is an ongoing process. As yet these descriptions have been created only for opcodes X'00' through X'0F'. The other opcode descriptions are to follow later.

This page contains the following three tables:
Base Set instructions.
Other Instructions.
Assembler Directives.

Base Set

Entries with a slightly darker background are no longer supported on current mainframe hardware and/or not supported by IBM's current version of HLASM. The associated mnemonics are printed in italics.
Opcodes that have no (known) mnemonic assigned to them are denoted by their hexadecimal opcode; these are explained below the table.
Extension sets have no associated mnemonic. These are denoted by their opcode in hexadecimal notation. These link to additional opcode tables.

Please note that instructions X'00' thru X'3F' are register-only operations. Adding X'40' generally yields the opcode of the associated register-and-storage instruction.

	_0	_1	_2	_3	_4	_5	_6	_7	_8	_9	_A	_B	_C	_D	_E	_F
0_	X'00'	X'01xx' XOPC			SPM	BALR	BCTR	BCR X'07m'	SSK	ISK	SVC	BSM	BASSM	BASR BASR	MVCL	CLCL
1_	LPR	LNR	LTR	LCR	NR	CLR	OR	XR	LR	CR	AR	SR	MR	DR	ALR	SLR
2_	LPDR	LNDR	LTDR	LCDR	HDR	LDXR LRDR	MXR	MXDR	LDR	CDR	ADR	SDR	MDR	DDR	AWR	SWR
3_	LPER	LNER	LTER	LCER	HER	LEDR LRER	AXR	SXR	LER	CER	AER	SER	MDER MER	DER	AUR	SUR
4_	STH	LA	STC	IC	EX	BAL	BCT	BC X'47m'	LH	CH	AH	SH	MH	BAS BAS	CVD	CVB
5_	ST	LAE	XDECO	XDECI	N	CL	O	X	L	C	A	S	M	D	AL	SL
6_	STD	XHEXI	XHEXO					MXD	LD	CD	AD	SD	MD	DD	AW	SW
7_	STE	MS							LE	CE	AE	SE	MDE ME	DE	AU	SU
8_	SSM	SPSW TRCD	LPSW	X'83' DIAG DIAGNOSE	BRXH JXH WRD	BRXLE JXLE RDD	BXH	BXLE	SRL	SLL	SRA	SLA	SRDL	SLDL	SRDA	SLDA
9_	STM	TM	MVI	TS	NI	CLI	OI	XI	LM	TRACE HPR	LAM TIOB	STAM CIO	SIO X'9C0x'	TIO X'9D0x'	HIO X'9E0x'	TCH X'9F0x'
A_	TRFET LMP		X'A2x'	X'A3x'	X'A4xx'	X'A5x' X'A5xx'	X'A6xx'	X'A7x'	MVCLE	CLCLE	BRFLG		STNSM	STOSM	SIGP X'AE.fc'	MC
B_	CTP STMC	LRA	X'B2xx'	X'B3xx'	IPB	SPB	STCTL	LCTL	LFI LMC	X'B9xx'	CS	CDS		CLM	STCM	ICM
C_	X'C0x'		X'C2x'		X'C4x'	BPRP	X'C6x'	BPP	X'C8x'				X'CCx'
D_	TRTR XIO	MVN	MVC	MVZ	NC	CLC	OC	XC	RSP	MVCK	MVCP	MVCS	TR	TRT	ED	EDMK
E_	X'E00x'	PKU XDUMP	UNPKU	X'E3xx'	X'E4xx'	X'E5xx'	X'E6xx' X'E6xx'	X'E7xx' X'E7xx'	MVCIN	PKA	UNPKA X'EAxx'	X'EBxx'	X'ECxx'	X'EDxx'	PLO X'EE.fc'	LMD
F_	SRP	MVO	PACK	UNPK					ZAP	CP	AP	SP	MP	DP

X'00' = Invalid Operation / Abend S0C1
X'83' = Diagnose

Other Instructions

Some instructions do not fit in the tables because their opcodes are currently unknown. Specifically this is the case for the instructions below. These are all either Coupling Facility (CF) instructions, or MicroCode (MC) instructions. We do know a few opcodes that have been assigned to Coupling Facility instructions, but we have not been able to link any of these to one of the instructions below.

For PXLO we know of various subfunctions, what we know has been included in the table. SYSOP, too, appears to support subfunctions, unfortunately, we have not been able to locate any details at all.

The empty slots indicate instructions that we have been able to associate with an opcode after all.

Facility	Operation description	Facility	Operation description	Facility	Mnemonic	Operation description	Facility	Mnemonic	Subfunction description
CF		MC		MC	BRS	Branch Relative Special	MC	PXLO	Invalidate Page Table Entry
CF	Test Vector Entry	MC		MC	DIP	Drain Instruction Pipeline	MC	PXLO	Load Absolute Address
CF	Set Vector Entry	MC		MC	EXAR	EXtract Access Register	MC	PXLO	Load Address Space Control Element
CF	Test Vector Summary	MC		MC	EXARI	EXtract Access Register Indirect	MC	PXLO	Load Host Page Table Entry
CF		MC	AND Logical Immediate	MC	EXGRI	EXtract program General Register Indirect	MC	PXLO	Load Host Real Address
CF	Send Message	MC	OR Logical Immediate	MC	EXINT	EXtract INTerrupt	MC	PXLO	Load Page Table Entry
CF	test message	MC	Insert Immediate Special Register	MC	EXTV	EXTract Via register-operand register	MC	PXLO	Load Real Address
CF	Prepare Channel Buffer	MC	EXtract program General Register	MC	MCEND	MilliCode END	MC	PXLO	Purge Data Cache
CF	Signal Channel buffer	MC	Set Program General Register	MC	MSET	Millicode SET via register-operand register	MC	PXLO	Purge Instruction Cache
CF	Test Channel Buffer	MC		MC	MVCX	MoVe Characters eXecution	MC	PXLO	Purge TLB
CF	Move Channel Buffer Data	MC		MC	OSR	Or Special Register	MC	PXLO	Read TLB
CF	Locate Channel Buffer	MC	Set Program Access Register	MC	PXLO	Perform trans(X)Lator Operation	MC	PXLO	Write TLB
CF	Transfer Structure	MC	Set Program Access Register Indirect	MC	RIRPT	Reset InterRuPTion	MC	SYSOP	various subfunctions
				MC	SPGRI	Set Program General Register Indirect
				MC	SYSOP	SYStem OPeration
				MC	TMBP	Test Millicode Branch Points

Assembler Directives

Assembler directives have no opcodes associated with them. Therefore we list them in a separate table. Please see below.

Assembler Directive	Description	Macro Directive	Description	DC/DS Field Type	Description
ACONTROL	Assembler CONTROL	ACTR	Assembler CounTeR	A	Address
ADATA	Associated DATA	AGO	Assembler GO to	AD	Address in Doubleword
AEJECT	Assembler EJECT macro listing	AGOB	Assembler GO Backward	B	Binary data
ALIAS	ALIAS definition	AIF	Assembler IF	C	Character data
AMODE	Addressing MODE	AIFB	Assembler IF Backward	CA	Character data Ascii
CATTR	Class ATTRibutes	AINSERT	Assembler INSERT source line	CE	Character data Ebcdic
CCW	Channel Command Word	ANOP	Assembler No-OPeration	CU	Character data Unicode
CCW0	Channel Command Word format-0	AREAD	Assembler READ source record	D	Double hfp data
CCW1	Channel Command Word format-1	ASPACE	Assembler SPACE macro listing	DB	Double Bfp data
CEJECT	Conditional EJECT listing	GBLA	GloBaL Arithmetic variable	DD	Double Dfp data
CNOP	Computer No-OPeration	GBLB	GloBaL Boolean variable	DH	Double Hfp data
COM	COMmon control section	GBLC	GloBaL Character variable	E	Exponential hfp data
COPY	COPY member	LCLA	LoCaL Arithmetic variable	EB	Exponential Bfp data
CSECT	Control SECTion	LCLB	LoCaL Boolean variable	ED	Exponential Dfp data
CXD	Cumulative eXternal Dummy length	LCLC	LoCaL Character variable	EH	Exponential Hfp data
DC	Define Constant	MACRO	MACRO start	F	Fixed-point binary data
DROP	DROP	MEND	Macro END	FD	Fixed-point Doubleword binary data
DS	Define Storage	MEXIT	Macro EXIT	G	Graphic character data
DSECT	Dummy SECTion	MHELP	Macro HELP	H	Halfword signed binary data
DXD	Define eXternal Dummy section	MNOTE	Macro NOTE	J	J-type data length of external dummy section or class
EJECT	EJECT listing	SETA	SET Arithmetic variable	JD	J-type data Doubleword length of external dummy section or class
END	END assembly	SETAF	SET Arithmetic variable by external Function	L	Long exponential hfp data
ENTRY	ENTRY point	SETB	SET Boolean variable	LB	Long exponential Bfp data
EQU	EQUate	SETC	SET Character variable	LD	Long exponential Dfp data
EXITCTL	EXIT ConTroL values	SETCF	SET Character variable by external Function	LH	Long exponential Hfp data
EXTRN	EXTeRNal symbol			LQ	Long exponential hfp data Quadword aligned
ICTL	Input ConTroL			P	Packed decimal data
ISEQ	Input SEQuence checking			Q	Q-type data external dummy section offset
LOCTR	LOCaToR			QD	Q-type Doubleword data external dummy section offset
LTORG	LiTeral pool ORiGin			QY	Q-type Yonder external dummy section offset
OPSYN	OPcode SYNonym			R	Relocatable psect address
ORG	ORiGin			RD	Relocatable Doubleword psect address
POP	POP stacked status			S	Standard base-displacement address
PRINT	PRINT settings			SY	Standard Yonder base-displacement address
PROCESS	PROCESSing options			V	oVerlay address
PUNCH	PUNCH object record			VD	oVerlay Doubleword address
PUSH	PUSH status onto stack			X	heXadecimal data
REPRO	REPROduce as object record			Y	Y-type data address
RMODE	Residence MODE			Z	Zoned decimal data
RSECT	Reenterable SECTion
SPACE	SPACE listing
START	START assembly
TITLE	TITLE definition
USING	USING
WXTRN	Weak eXTeRNal
XATTR	eXternal ATTRibutes

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To the Base Set instructions.
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