				AS68 Summary

				V.R. Pratt
				Feb., 1981

The following are all the instruction opcodes recognized by as68.  Their usage
agrees closely with that of the 68000 User's Manual.


abcd	      clrb	    lsll	  smi
addb	      clrw	    lsrb	  sne
addw	      clrl	    lsrw	  spl
addl	      cmpb	    lsrl	  st
addqb	      cmpw	    movb	  stop
addqw	      cmpl	    movw	  subb
addql	      cmpmb	    movl	  subw
addxb	      cmpmw	    movemw	  subl
addxw	      cmpml	    moveml	  subqb
addxl	      dbcc	    movepw	  subqw
andb	      dbcs	    movepl	  subql
andw	      dbeq	    moveq	  subxb
andl	      dbf	    muls	  subxw
aslb	      dbra	    mulu	  subxl
aslw	      dbge	    nbcd	  svc
asll	      dbgt	    negb	  svs
asrb	      dbhi	    negw	  swap
asrw	      dble	    negl	  tas
asrl	      dbls	    negxb	  trap
bcc	      dblt	    negxw	  trapv
bccs	      dbmi	    negxl	  tstb
bchg	      dbne	    nop		  tstw
bclr	      dbpl	    notb	  tstl
bcs	      dbt	    notw	  unlk
bcss	      dbvc	    notl
beq	      dbvs	    orb
beqs	      divs	    orw
bge	      divu	    orl
bges	      eorb	    pea
bgt	      eorw	    reset
bgts	      eorl	    rolb
bhi	      exg	    rolw
bhis	      extw	    roll
ble	      extl	    rorb
bles	      jbsr	    rorw
bls	      jcc	    rorl
blss	      jcs	    roxlb
blt	      jeq	    roxlw
blts	      jge	    roxll
bmi	      jgt	    roxrb
bmis	      jhi	    roxrw
bne	      jle	    roxrl
bnes	      jls	    rte
bpl	      jlt	    rtr
bpls	      jmi	    rts
bra	      jmp	    sbcd
bras	      jne	    scc
bset	      jpl	    scs
bsr	      jra	    seq
bsrs	      jsr	    sf
btst	      jvc	    sge
bvc	      jvs	    sgt
bvcs	      lea	    shi
bvs	      link	    sle
bvss	      lslb	    sls
chk	      lslw	    slt



				Pseudo-ops

=		direct assignment
.end		end of file (optional)
.long		long datum
.word		word datum
.byte		byte datum
.macro		define macro
.rept		repeat following
.ascii
.asciz
.blkb
.blkw
.blkl
.list
.nlist
.insrt
.text		following goes in text area
.data		following goes in data area
.bss		following goes in bss area
.globl		argument is global symbol
.comm		argument 1 is bss symbol; set aside arg 2 bytes for it
.radix		set input radix (default decimal)
.typef
.printf		print arg in listing
.error		announce error
.page		listing skips to new page
.defrs
.even		align to word boundary
.if		conditional
.ift		if true
.iff		if false

				Expression Syntax

Expressions are parenthesized with [ ] and may use any of the following  C
operators, 
+ - * / & ! ^ << >> %
Association is left to right and there is no precedence.

Hexadecimal constants are preceded with '/', decimal are followed with '.'
(redundant unless the pseudo-op '.radix' is used since the default radix for
integers is decimal).  We plan to convert soon to an MIT revision of the
assembler in which all constants are written using C conventions; thus /f00d
becomes 0xf00d.

A vertical bar (|) begins a comment, which continues to the end of the line.

Legal address forms are as follows.  N stands for any expression, I for an
integer from 0 to 7, all other characters stand for themselves. sp may be used
in place of a7.

N			Absolute address
dI			Data register direct
aI			Address register direct
aI@			Indirect
aI@(N)			Indirect with Displacement
aI@+			Indirect with Postincrement
aI@-			Indirect with Predecrement
aI@(N,rI:s)		Indirect with Index (reg r = d or a, size s = w or l)
pc@(N)			Program Counter with Displacement
pc@(N,rI:s)		Prog Ctr with Index (reg r = d or a, size s = w or l)
sr			status register
cc			condition code register (right half of sr)
usp			user stack pointer (can only move to and from aI)
#N			immediate data
