68k instructions timings: Difference between revisions

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TODO: CSS template for cputiming is ugly and broken.
Mirrored information from [[http://oldwww.nvg.ntnu.no/amiga/MC680x0_Sections/mc68000timing.HTML oldwww.nvg.ntnu.no]]


Mirroring information from http://oldwww.nvg.ntnu.no/amiga/MC680x0_Sections/mc68000timing.HTML
The number of bus '''r'''ead and '''w'''rite cycles are shown in parenthesis as (r/w). Any other cycles are internal.


The number of bus read and write cycles is shown in parenthesis as (r/w).
In the following tables, the headings have the following meanings:
 
In the following tables the headings have the following meanings:  
* An : Address register operand
* An : Address register operand
* Dn : Data register operand
* Dn : Data register operand
Line 11: Line 9:
* M : Memory effective address operand
* M : Memory effective address operand


To get the execution time, multiply the cycles count by 83.33ns ([[Clock|1/12MHz]]).
To get the real execution time, multiply the total cycles count by 83.33ns ([[Clock|1/12MHz]]). An example is given in each section.


A [[68k interrupts|VBlank interrupt]] lasts exactly 40 lines * 384 pixels * 2 = 30720 cycles (2.56ms).
The [[68k interrupts|vertical blank]] lasts exactly 40 lines * 384 pixels * 2 cycles per pixel = 30720 cycles (2.56ms).


See [[optimization]].


=Effective address operand calculation=
=Effective address operand calculation=
Line 20: Line 19:
This table lists the number of clock periods required to compute an instruction's effective address. It includes fetching of any extension words, the address computation, and fetching of the memory operand.
This table lists the number of clock periods required to compute an instruction's effective address. It includes fetching of any extension words, the address computation, and fetching of the memory operand.


Note: there are no write cycles involved in processing the effective address.
{|class="wikitable"
 
!Syntax||Adressing mode||B,W||L
{|class="cputiming"
|'''Syntax'''
|'''Adressing mode'''
|'''B,W'''
|'''L'''
|-
|-
|Dn
|Dn
|Data register direct
|Data register direct
|style="background-color:#7F7;"|0(0/0)
|class="green"|0(0/0)
|style="background-color:#7F7;"|0(0/0)
|class="green"|0(0/0)
|-
|-
|An
|An
|Address register direct
|Address register direct
|style="background-color:#7F7;"|0(0/0)
|class="green"|0(0/0)
|style="background-color:#7F7;"|0(0/0)
|class="green"|0(0/0)
|-
|-
|(An)
|(An)
|Address register indirect
|Address register indirect
|4(1/0)
|class="green"|4(1/0)
|8(2/0)
|class="yellow"|8(2/0)
|-
|-
|(An)+
|(An)+
|Address register indirect, post inc.
|Address register indirect, post inc.
|4(1/0)
|class="green"|4(1/0)
|8(2/0)
|class="yellow"|8(2/0)
|-
|-
| -(An)
| -(An)
|Address register indirect, pre dec.
|Address register indirect, pre dec.
|6(1/0)
|class="yellow"|6(1/0)
|10(2/0)
|class="orange"|10(2/0)
|-
|-
|d(An)
|d(An)
|Address register indirect, displacement
|Address register indirect, displacement
|8(2/0)
|class="yellow"|8(2/0)
|12(3/0)
|class="orange"|12(3/0)
|-
|-
|d(An,ix)
|d(An,ix)
|Address register indirect, index
|Address register indirect, index
|10(2/0)
|class="orange"|10(2/0)
|14(3/0)
|class="red"|14(3/0)
|-
|-
|xxx.w
|xxx.w
|Absolute short
|Absolute short
|8(2/0)
|class="yellow"|8(2/0)
|12(3/0)
|class="orange"|12(3/0)
|-
|-
|xxx.l
|xxx.l
|Absolute long
|Absolute long
|style="background-color:#F77;"|12(3/0)
|class="orange"|12(3/0)
|style="background-color:#F77;"|16(4/0)
|class="red"|16(4/0)
|-
|-
|d(PC)
|d(PC)
|PC with displacement
|PC with displacement
|8(2/0)
|class="yellow"|8(2/0)
|12(3/0)
|class="orange"|12(3/0)
|-
|-
|d(PC,ix)
|d(PC,ix)
|PC with index
|PC with index
|10(2/0)
|class="yellow"|10(2/0)
|14(3/0)
|class="red"|14(3/0)
|-
|-
|#xxx
|#xxx
|Immediate
|Immediate
|4(1/0)
|class="green"|4(1/0)
|8(2/0)
|class="yellow"|8(2/0)
|}
|}


The size of the index register (ix) does not affect execution time
Notes:
 
* Pre-dec is slower than post-inc
* There are no write cycles involved in processing the effective address
* The size of the index register (ix) does not affect execution time


=Move instructions=
=Move instructions=
Line 97: Line 93:


==Byte and word==
==Byte and word==
Example: '''move.b (a0)+,$10201D''' (Byte (An)+ to xxx.L) takes 20 cycles.


{|class="wikitable"
{|class="wikitable"
Line 102: Line 100:
|-
|-
!Dn
!Dn
| 4(1/0) || 4(1/0) || 8(1/1) || 8(1/1) || 8(1/1) || 12(2/1) || 14(2/1) || 12(2/1) || 16(3/1)
|class="green"|4(1/0)||class="green"|4(1/0)||class="green"|8(1/1)||class="green"|8(1/1)
|class="green"|8(1/1)||class="yellow"|12(2/1)||class="yellow"|14(2/1)||class="yellow"|12(2/1)||class="yellow"|16(3/1)
|-
|-
!An
!An
|4(1/0)||4(1/0)||8(1/1)||8(1/1)||8(1/1)||12(2/1)||14(2/1)||12(2/1)||16(3/1)
|class="green"|4(1/0)||class="green"|4(1/0)||class="green"|8(1/1)||class="green"|8(1/1)
|class="green"|8(1/1)||class="yellow"|12(2/1)||class="yellow"|14(2/1)||class="yellow"|12(2/1)||class="yellow"|16(3/1)
|-
|-
!(An)
!(An)
|8(2/0)||8(2/0)||12(2/1)||12(2/1)||12(2/1)||16(3/1)||18(3/1)||16(3/1)||20(4/1)
|class="green"|8(2/0)||class="green"|8(2/0)||class="yellow"|12(2/1)||class="yellow"|12(2/1)
|class="yellow"|12(2/1)||class="yellow"|16(3/1)||class="orange"|18(3/1)||class="yellow"|16(3/1)||class="orange"|20(4/1)
|-
|-
!(An)+
!(An)+
|8(2/0)||8(2/0)||12(2/1)||12(2/1)||12(2/1)||16(3/1)||18(3/1)||16(3/1)||20(4/1)
|class="green"|8(2/0)||class="green"|8(2/0)||class="yellow"|12(2/1)||class="yellow"|12(2/1)||class="yellow"|12(2/1)
|class="yellow"|16(3/1)||class="orange"|18(3/1)||class="yellow"|16(3/1)||class="orange"|20(4/1)
|-
|-
!-(An)
!-(An)
|10(2/0)||10(2/0)||14(2/1)||14(2/1)||14(2/1)||18(3/1)||20(4/1)||18(3/1)||22(4/1)
|class="green"|10(2/0)||class="green"|10(2/0)||class="yellow"|14(2/1)||class="yellow"|14(2/1)||class="yellow"|14(2/1)
|class="orange"|18(3/1)||class="orange"|20(4/1)||class="orange"|18(3/1)||class="orange"|22(4/1)
|-
|-
!d(An)
!d(An)
|12(3/0)||12(3/0)||16(3/1)||16(3/1)||16(3/1)||20(4/1)||22(4/1)||20(4/1)||24(5/1)
|class="yellow"|12(3/0)||class="yellow"|12(3/0)||class="yellow"|16(3/1)||class="yellow"|16(3/1)||class="yellow"|16(3/1)
|class="orange"|20(4/1)||class="orange"|22(4/1)||class="orange"|20(4/1)||class="red"|24(5/1)
|-
|-
!d(An,ix)
!d(An,ix)
|14(3/0)||14(3/0)||18(3/1)||18(3/1)||18(3/1)||22(4/1)||24(4/1)||22(4/1)||26(5/1)
|class="yellow"|14(3/0)||class="yellow"|14(3/0)||class="orange"|18(3/1)||class="orange"|18(3/1)||class="orange"|18(3/1)
|class="orange"|22(4/1)||class="red"|24(4/1)||class="orange"|22(4/1)||class="red"|26(5/1)
|-
|-
!xxx.W
!xxx.W
|12(3/0)||12(3/0)||16(3/1)||16(3/1)||16(3/1)||20(4/1)||22(4/1)||20(4/1)||24(5/1)
|class="yellow"|12(3/0)||class="yellow"|12(3/0)||class="yellow"|16(3/1)||class="yellow"|16(3/1)||class="yellow"|16(3/1)
|class="orange"|20(4/1)||class="orange"|22(4/1)||class="orange"|20(4/1)||class="red"|24(5/1)
|-
|-
!xxx.L
!xxx.L
|16(4/0)||16(4/0)||20(4/1)||20(4/1)||20(4/1)||24(5/1)||26(5/1)||24(5/1)||28(6/1)
|class="yellow"|16(4/0)||class="yellow"|16(4/0)||class="orange"|20(4/1)||class="orange"|20(4/1)||class="orange"|20(4/1)
|class="red"|24(5/1)||class="red"|26(5/1)||class="red"|24(5/1)||class="red"|28(6/1)
|-
|-
!d(PC)
!d(PC)
|12(3/0)||12(3/0)||16(3/1)||16(3/1)||16(3/1)||20(4/1)||22(4/1)||20(4/1)||24(5/1)
|class="yellow"|12(3/0)||class="yellow"|12(3/0)||class="yellow"|16(3/1)||class="yellow"|16(3/1)||class="yellow"|16(3/1)
|class="orange"|20(4/1)||class="orange"|22(4/1)||class="orange"|20(4/1)||class="red"|24(5/1)
|-
|-
!d(PC,ix)
!d(PC,ix)
|14(3/0)||14(3/0)||18(3/1)||18(3/1)||18(3/1)||22(4/1)||24(4/1)||22(4/1)||26(5/1)
|class="yellow"|14(3/0)||class="yellow"|14(3/0)||class="orange"|18(3/1)||class="orange"|18(3/1)||class="orange"|18(3/1)
|class="orange"|22(4/1)||class="red"|24(4/1)||class="orange"|22(4/1)||class="red"|26(5/1)
|-
|-
!#xxx
!#xxx
|8(2/0)||8(2/0)||12(2/1)||12(2/1)||12(2/1)||16(3/1)||18(3/1)||16(3/1)||20(4/1)
|class="green"|8(2/0)||class="green"|8(2/0)||class="yellow"|12(2/1)||class="yellow"|12(2/1)||class="yellow"|12(2/1)
|class="yellow"|16(3/1)||class="orange"|18(3/1)||class="yellow"|16(3/1)||class="orange"|20(4/1)
|}
|}


Line 142: Line 152:
==Long==
==Long==


<syntaxhighlight lang="text">
Example: '''move.l $05012C,4(a1,d0)''' (Long xxx.L to d(An,ix)) takes 34 cycles.
    Dn An (An) (An)+ -(An) d(An) d(An,ix) xxx.W |xxx.L


Dn 4(1/0) 4(1/0) 12(1/2) 12(1/2) 12(1/2) 16(2/2) 18(2/2) 16(2/2) 20(3/2)
{|class="wikitable"
An 4(1/0) 4(1/0) 12(1/2) 12(1/2) 12(1/2) 16(2/2) 18(2/2) 16(2/2) 20(3/2)
!&nbsp; || Dn || An || (An) || (An)+ || -(An) || d(An) || d(An,ix) || xxx.W || xxx.L
(An) 12(3/0) 12(3/0) 20(3/2) 20(3/2) 20(3/2) 24(4/2) 26(4/2) 24(4/2) 28(5/2)
|-
(An)+ 12(3/0) 12(3/0) 20(3/2) 20(3/2) 20(3/2) 24(4/2) 26(4/2) 24(4/2) 28(5/2)
!Dn
-(An) 14(3/0) 14(3/0) 22(3/2) 22(3/2) 22(3/2) 26(4/2) 28(4/2) 26(4/2) 30(5/2)
|class="green"|4(1/0)||class="green"|4(1/0)||class="green"|12(1/2)||class="green"|12(1/2)||class="green"|12(1/2)
d(An) 16(4/0) 16(4/0) 24(4/2) 24(4/2) 24(4/2) 28(5/2) 30(5/2) 28(5/2) 32(6/2)
|class="yellow"|16(2/2)||class="yellow"|18(2/2)||class="yellow"|16(2/2)||class="yellow"|20(3/2)
d(An,ix)18(4/0) 18(4/0) 26(4/2) 26(4/2) 26(4/2) 30(5/2) 32(5/2) 30(5/2) 34(6/2)
|-
xxx.W 16(4/0) 16(4/0) 24(4/2) 24(4/2) 24(4/2) 28(5/2) 30(5/2) 28(5/2) 32(6/2)
!An
xxx.L 20(5/0) 20(5/0) 28(5/2) 28(5/2) 28(5/2) 32(6/2) 34(6/2) 32(6/2) 36(7/2)
|class="green"|4(1/0)||class="green"|4(1/0)||class="green"|12(1/2)||class="green"|12(1/2)||class="green"|12(1/2)
d(PC) 16(4/0) 16(4/0) 24(4/2) 24(4/2) 24(4/2) 28(5/2) 30(5/2) 28(5/2) 32(5/2)
|class="yellow"|16(2/2)||class="yellow"|18(2/2)||class="yellow"|16(2/2)||class="yellow"|20(3/2)
d(PC,ix)18(4/0) 18(4/0) 26(4/2) 26(4/2) 26(4/2) 30(5/2) 32(5/2) 30(5/2) 34(6/2)
|-
#xxx 12(3/0) 12(3/0) 20(3/2) 20(3/2) 20(3/2) 24(4/2) 26(4/2) 24(4/2) 28(5/2)
!(An)
 
|class="green"|12(3/0)||class="green"|12(3/0)||class="yellow"|20(3/2)||class="yellow"|20(3/2)||class="yellow"|20(3/2)
The size of the index register (ix) does not affect execution time
|class="orange"|24(4/2)||class="orange"|26(4/2)||class="orange"|24(4/2)||class="orange"|28(5/2)
</syntaxhighlight>
|-
!(An)+
|class="green"|12(3/0)||class="green"|12(3/0)||class="yellow"|20(3/2)||class="yellow"|20(3/2)||class="yellow"|20(3/2)
|class="orange"|24(4/2)||class="orange"|26(4/2)||class="orange"|24(4/2)||class="orange"|28(5/2)
|-
!-(An)
|class="yellow"|14(3/0)||class="yellow"|14(3/0)||class="orange"|22(3/2)||class="orange"|22(3/2)||class="orange"|22(3/2)
|class="orange"|26(4/2)||class="orange"|28(4/2)||class="orange"|26(4/2)||class="red"|30(5/2)
|-
!d(An)
|class="yellow"|16(4/0)||class="yellow"|16(4/0)||class="orange"|24(4/2)||class="orange"|24(4/2)||class="orange"|24(4/2)
|class="orange"|28(5/2)||class="red"|30(5/2)||class="orange"|28(5/2)||class="red"|32(6/2)
|-
!d(An,ix)
|class="yellow"|18(4/0)||class="yellow"|18(4/0)||class="orange"|26(4/2)||class="orange"|26(4/2)||class="orange"|26(4/2)
|class="red"|30(5/2)||class="red"|32(5/2)||class="red"|30(5/2)||class="red"|34(6/2)
|-
!xxx.W
|class="yellow"|16(4/0)||class="yellow"|16(4/0)||class="orange"|24(4/2)||class="orange"|24(4/2)||class="orange"|24(4/2)
|class="orange"|28(5/2)||class="red"|30(5/2)||class="orange"|28(5/2)||class="red"|32(6/2)
|-
!xxx.L
|class="yellow"|20(5/0)||class="yellow"|20(5/0)||class="orange"|28(5/2)||class="orange"|28(5/2)||class="orange"|28(5/2)
|class="red"|32(6/2)||class="red"|34(6/2)||class="red"|32(6/2)||class="red"|36(7/2)
|-
!d(PC)
|class="yellow"|16(4/0)||class="yellow"|16(4/0)||class="orange"|24(4/2)||class="orange"|24(4/2)||class="orange"|24(4/2)
|class="orange"|28(5/2)||class="red"|30(5/2)||class="orange"|28(5/2)||class="red"|32(5/2)
|-
!d(PC,ix)
|class="yellow"|18(4/0)||class="yellow"|18(4/0)||class="orange"|26(4/2)||class="orange"|26(4/2)||class="orange"|26(4/2)
|class="red"|30(5/2)||class="red"|32(5/2)||class="red"|30(5/2)||class="red"|34(6/2)
|-
!#xxx
|class="green"|12(3/0)||class="green"|12(3/0)||class="yellow"|20(3/2)||class="yellow"|20(3/2)||class="yellow"|20(3/2)
|class="orange"|24(4/2)||class="orange"|26(4/2)||class="orange"|24(4/2)||class="orange"|28(5/2)
|}


The size of the index register (ix) does not affect execution time.


=Standard instructions=
=Standard instructions=


<syntaxhighlight lang="text">
Example: '''add.w d3,a7''' (Word ea Dn + An) takes 8 cycles.
The number of clock periods shown in this table indicates the time required
to perform the operations, store the results and read the next instruction.
The number of clock periods and the number of read and write cycles must be
added respectively to those of the effective address calculation where
indicated.


instruction Size op<ea>,An ^ op<ea>,Dn op Dn,<M>
The number of clock periods shown in this table indicates the time required to perform the operations, store the results and read the next instruction. The total number of clock periods must be added respectively to those of the effective address calculation where indicated (+).


ADD byte,word 8(1/0) +   4(1/0) + 8(1/1) +
{|class="wikitable"
  long 6(1/0) +**   6(1/0) +** 12(1/2) +
!&nbsp; || Size || <ea>,An * || <ea>,Dn || Dn,<M>
AND byte,word   -   4(1/0) + 8(1/1) +
|-
  long   -   6(1/0) +** 12(1/2) +
!rowspan=2|ADD
CMP byte,word 6(1/0) +   4(1/0) +   -
|B,W
  long 6(1/0) +   6(1/0) +   -
|class="orange"|8(1/0)+||class="green"|4(1/0)+||class="orange"|8(1/1)+
DIVS     -   - 158(1/0) +*   -
|-
DIVU     -   - 140(1/0) +*   -
|L
EOR byte,word   -   4(1/0) *** 8(1/1) +
|class="yellow"|6(1/0)+**||class="yellow"|6(1/0)+**||class="red"|12(1/2)+
  long   -   8(1/0) *** 12(1/2) +
|-
MULS     -   - 70(1/0) +*   -
!rowspan=2|AND
MULU     -   - 70(1/0) +*   -
|B,W
OR byte,word   -   4(1/0) +** 8(1/1) +
| - ||class="green"|4(1/0)+||class="orange"|8(1/1)+
  long   -   6(1/0) +** 12(1/2) +
|-
SUB byte,word 8(1/0) +   4(1/0) + 8(1/1) +
|L
  long 6(1/0) +**   6(1/0) +** 12(1/2) +
| - ||class="yellow"|6(1/0)+**||class="red"|12(1/2)+
|-
!rowspan=2|CMP
|B,W
|class="yellow"|6(1/0)+||class="green"|4(1/0)+|| -
|-
|L
|class="yellow"|6(1/0)+||class="yellow"|6(1/0)+|| -
|-
!DIVS
| - || - ||class="red"|158(1/0)+|| -
|-
!DIVU
| - || - ||class="red"|140(1/0)+|| -
|-
!rowspan=2|EOR
|B,W
| - ||class="green"|4(1/0) ***||class="orange"|8(1/1) +
|-
|L
| - ||class="orange"|8(1/0) ***||class="red"|12(1/2) +
|-
!MULS
| - || - ||class="red"|70(1/0)+*|| -
|-
!MULU
| - || - ||class="red"|70(1/0)+*|| -
|-
!rowspan=2|OR
|B,W
| - ||class="green"|4(1/0) +**||class="orange"|8(1/1) +
|-
|L
| - ||class="yellow"|6(1/0) +**||class="red"|12(1/2) +
|-
!rowspan=2|SUB
|B,W
|class="orange"|8(1/0)+||class="green"|4(1/0)+||class="orange"|8(1/1)+
|-
|L
|class="yellow"|6(1/0)+**||class="yellow"|6(1/0)+**||class="red"|12(1/2)+
|}


<syntaxhighlight lang="text">
notes: + Add effective address calculation time
notes: + Add effective address calculation time
^ Word or long only
^ Word or long only
Line 204: Line 287:
    n is defined as:
    n is defined as:
MULU: n = the number of ones in the <ea>
MULU: n = the number of ones in the <ea>
MULS: n = concatanate the <ea> with a zero as the LSB;
MULS: n = concatenate the <ea> with a zero as the LSB;
  n is the resultant number of 10 or 01 patterns
  n is the resultant number of 10 or 01 patterns
  in the 17-bit source; i.e., worst case happens
  in the 17-bit source; i.e., worst case happens
  when the source is $5555
  when the source is $5555
</syntaxhighlight>
</syntaxhighlight>


=Immediate instructions=
=Immediate instructions=


<syntaxhighlight lang="text">
The number of clock periods periods shown in this table includes the time to fetch immediate operands, perform the operations, store the results and read the next operation. The total number of clock periods must be added respectively to those of the effective address calculation where indicated (+).
The number of clock periods periods shown in this table includes the time to
fetch immediate operands, perform the operations, store the results and read  
the next operation. The number of clock periods and the number of read and
write cycles must be added respectively to those of the effective address
calculation where indicated.


instruction size op #,Dn op #,An op #,M
{|class="wikitable"
 
!&nbsp; || Size || #,Dn || #,An || #,M
ADDI byte,word 8(2/0)   - 12(2/1) +
|-
  long 16(3/0)   - 20(3/2) +
!rowspan=2|ADDI
ADDQ byte,word 4(1/0) 8(1/0) * 8(1/1) +
|B,W
  long 8(1/0) 8(1/0) 12(1/2) +
|class="green"|8(2/0)|| - ||class="yellow"|12(2/1)+
ANDI byte,word 8(2/0)   - 12(2/1) +
|-
  long 16(3/0)   - 20(3/1) +
|L
CMPI byte,word 8(2/0)   - 8(2/0) +
|class="orange"|16(3/0)|| - ||class="red"|20(3/2)+
  long 14(3/0)   - 12(3/0) +
|-
EORI byte,word 8(2/0)   - 12(2/1) +
!rowspan=2|ADDQ
  long 16(3/0)   - 20(3/2) +
|B,W
MOVEQ   long 4(1/0)   -   -
|class="green"|4(1/0)||class="yellow"|8(1/0)*||class="orange"|12(1/2)+
ORI byte,word 8(2/0)   - 12(2/1) +
|-
  long 16(3/0)   - 20(3/2) +
|L
SUBI byte,word 8(2/0)   - 12(2/1) +
|class="yellow"|8(1/0)||class="yellow"|8(1/0)||class="orange"|12(1/2)+
  long 16(3/0)   - 20(3/2) +
|-
SUBQ byte,word 4(1/0) 8(1/0) * 8(1/1) +
!rowspan=2|ANDI
  long 8(1/0) 8(1/0) 12(1/2) +
|B,W
|class="green"|8(2/0)|| - ||class="yellow"|12(1/2)+
|-
|L
|class="orange"|16(3/0)|| - ||class="red"|20(3/1)+
|-
!rowspan=2|CMPI
|B,W
|class="green"|8(2/0)|| - ||class="green"|8(2/0)+
|-
|L
|class="orange"|14(3/0)|| - ||class="yellow"|12(3/1)+
|-
!rowspan=2|EORI
|B,W
|class="green"|8(2/0)|| - ||class="yellow"|12(2/1)+
|-
|L
|class="orange"|16(3/0)|| - ||class="red"|20(3/2)+
|-
!MOVEQ
|L
|class="green"|4(1/0)|| - || -
|-
!rowspan=2|ORI
|B,W
|class="green"|8(2/0)|| - ||class="yellow"|12(2/1)+
|-
|L
|class="orange"|16(3/0)|| - ||class="red"|20(3/2)+
|-
!rowspan=2|SUBI
|B,W
|class="green"|8(2/0)|| - ||class="yellow"|12(2/1)+
|-
|L
|class="orange"|16(3/0)|| - ||class="red"|20(3/2)+
|-
!rowspan=2|SUBQ
|B,W
|class="green"|4(1/0)||class="yellow"|8(1/0)*||class="yellow"|8(1/1)+
|-
|L
|class="yellow"|8(1/0)||class="yellow"|8(1/0)||class="orange"|12(1/2)+
|}


<syntaxhighlight lang="text">
+ Add effective address calculation time
+ Add effective address calculation time
* word only
* word only
</syntaxhighlight>
</syntaxhighlight>


=Single operand instructions=
=Single operand instructions=
Line 255: Line 376:
instruction size register memory
instruction size register memory


CLR byte,word 4(1/0) 8(1/1) +
CLR byte,word 4(1/0) 8(1/1) +
  long 6(1/0) 12(1/2) +
  long 6(1/0) 12(1/2) +
NBCD   byte 6(1/0) 8(1/1) +
NBCD   byte 6(1/0) 8(1/1) +
NEG byte,word 4(1/0) 8(1/1) +
NEG byte,word 4(1/0) 8(1/1) +
  long 6(1/0) 12(1/2) +
  long 6(1/0) 12(1/2) +
NEGX byte,word 4(1/0) 8(1/1) +
NEGX byte,word 4(1/0) 8(1/1) +
  long 6(1/0) 12(1/2) +
  long 6(1/0) 12(1/2) +
NOT byte,word 4(1/0) 8(1/1) +
NOT byte,word 4(1/0) 8(1/1) +
  long 6(1/0) 12(1/2) +
  long 6(1/0) 12(1/2) +
Scc byte,false 4(1/0) 8(1/1) +
Scc byte,false 4(1/0) 8(1/1) +
byte,true 6(1/0) 8(1/1) +
byte,true 6(1/0) 8(1/1) +
TAS #   byte 4(1/0) 10(1/1) +
TAS #   byte 4(1/0) 10(1/1) +
TST byte,word 4(1/0) 4(1/0) +
TST byte,word 4(1/0) 4(1/0) +
  long 4(1/0) 4(1/0) +
  long 4(1/0) 4(1/0) +


+ add effective address calculation time
+ add effective address calculation time
Line 274: Line 395:
           read/write cycle can disrupt system DMA.
           read/write cycle can disrupt system DMA.
</syntaxhighlight>
</syntaxhighlight>


=Shift and rotate instructions=
=Shift and rotate instructions=
Line 287: Line 407:


ASR,ASL byte,word 6+2n(1/0) 8(1/1) +
ASR,ASL byte,word 6+2n(1/0) 8(1/1) +
  long 8+2n(1/0)   -
  long 8+2n(1/0)   -
LSR,LSL byte,word 6+2n(1/0) 8(1/1) +
LSR,LSL byte,word 6+2n(1/0) 8(1/1) +
  long 8+2n(1/0)   -
  long 8+2n(1/0)   -
ROR,ROL byte,word 6+2n(1/0) 8(1/1) +
ROR,ROL byte,word 6+2n(1/0) 8(1/1) +
  long 8+2n(1/0)   -
  long 8+2n(1/0)   -
ROXR,ROXL byte,word 6+2n(1/0) 8(1/1) +
ROXR,ROXL byte,word 6+2n(1/0) 8(1/1) +
  long 8+2n(1/0)   -
  long 8+2n(1/0)   -


+ add effective address calculation time
+ add effective address calculation time
n is the shift or rotate count
n is the shift or rotate count
</syntaxhighlight>
</syntaxhighlight>


=Bit manipulation instructions=
=Bit manipulation instructions=
Line 308: Line 427:
calculation where indicated. Dynamic: register, static: immediate.
calculation where indicated. Dynamic: register, static: immediate.


instruction size dynamic static
instruction size           dynamic                 static
register  memory register  memory
                        register  memory       register  memory
BCHG byte   -   8(1/1) +   -   12(2/1) +
BCHG         byte         -       8(1/1) +       -       12(2/1) +
long 8(1/0) *    - 12(2/0) *    -
            long       8(1/0) *    -         12(2/0) *    -
BCLR byte   -   8(1/1) +   -   12(2/1) +
BCLR         byte         -       8(1/1) +       -       12(2/1) +
long 10(1/0) *    - 14(2/0) *    -
            long       10(1/0) *    -         14(2/0) *    -
BSET byte   -   8(1/1) +   -   12(2/1) +
BSET         byte         -       8(1/1) +       -       12(2/1) +
long 8(1/0) *    - 12(2/0) *    -
            long       8(1/0) *    -         12(2/0) *    -
BTST byte   -    4(1/0) +   -     8(2/0) +
BTST         byte         -    4(1/0) +       -       8(2/0) +
long 6(1/0)     - 10(2/0)      -
            long       6(1/0)      -         10(2/0)      -


+ add effective address calculation time
+ add effective address calculation time
* indicates maximum value
* indicates maximum value
</syntaxhighlight>
</syntaxhighlight>


=Conditional instructions=
=Conditional instructions=


{|class="cputiming"
{|class="wikitable"
|'''Syntax'''
!Mnemonic || Displacement || Branch taken || Not taken
|'''Displacement'''
|'''Branch taken'''
|'''Not taken'''
|-
|-
|rowspan=2|Bcc
|rowspan=2|Bcc
|byte
|byte
|10(2/0)
|class="yellow"|10(2/0)||class="green"|8(1/0)
|8(1/0)
|-
|-
|word
|word
|10(2/0)
|class="yellow"|10(2/0)||class="orange"|12(1/0)
|12(1/0)
|-
|-
|rowspan=2|BRA
|rowspan=2|BRA
|byte
|byte
|10(2/0)
|class="yellow"|10(2/0)
|
|
|-
|-
|word
|word
|10(2/0)
|class="yellow"|10(2/0)
|
|
|-
|-
|rowspan=2|BSR
|rowspan=2|BSR
|byte
|byte
|18(2/2)
|class="red"|18(2/2)
|
|
|-
|-
|word
|word
|18(2/2)
|class="red"|18(2/2)
|
|
|-
|-
Line 362: Line 475:
|cc true
|cc true
|
|
|12(2/0)
|class="orange"|12(2/0)
|-
|-
|cc false
|cc false
|10(2/0)
|class="yellow"|10(2/0)
|style="background-color:#F77;"|14(3/0)
|class="orange"|14(3/0)
|}
|}


=JMP, JSR, LEA, PEA and MOVEM instructions=
=JMP, JSR, LEA, PEA and MOVEM instructions=
Line 377: Line 489:
move multiple registers instructions.
move multiple registers instructions.


instr size (An) (An)+ -(An) d(An)
instr size   (An) (An)+ -(An) d(An) d(An,ix)+  xxx.W      xxx.L      d(PC)      d(PC,ix)*
JMP -   8(2/0)   -   - 10(2/0)
JMP     -     8(2/0)     -       -   10(2/0) 14(3/0)    10(2/0)    12(3/0)   10(2/0)    14(3/0)
JSR - 16(2/2)   -   - 18(2/2)
JSR     -   16(2/2)     -       -   18(2/2) 22(2/2)    18(2/2)    20(3/2)   18(2/2)    22(2/2)
LEA -   4(1/0)   -   - 8(2/0)
LEA     -     4(1/0)     -       -     8(2/0) 12(2/0)    8(2/0)    12(3/0)   8(2/0)    12(2/0)
PEA - 12(1/2)   -   - 16(2/2)
PEA     -   12(1/2)     -       -   16(2/2) 20(2/2)    16(2/2)    20(3/2)   16(2/2)    20(2/2)
MOVEM word   12+4n   12+4n   -   16+4n
MOVEM   word     12+4n      12+4n       -      16+4n   18+4n      16+4n      20+4n     16+4n      18+4n
M->R (3+n/0) (3+n/0)   - (4+n/0)
M->R           (3+n/0)   (3+n/0)       -   (4+n/0) (4+n/0)    (4+n/0)    (5+n/0)   (4+n/0)    (4+n/0)
long   12+8n   12+8n   -   16+8n
    long     12+8n     12+8n       -     16+8n   18+8n      16+8n      20+8n     16+8n      18+8n
(3+2n/0) (3+2n/0)   -    (4+2n/0)
      (3+2n/0)    (3+2n/0)       -  (4+2n/0) (4+2n/0)  (4+2n/0)  (5+2n/0) (4+2n/0)  (4+2n/0)
MOVEM word     8+4n   -   8+4n   12+4n
MOVEM word   8+4n     -     8+4n 12+4n    14+4n      12+4n      16+4n     - -
R->M   (2/n)   - (2/n)   (3/n)
R->M     (2/n)     -     (2/n) (3/n)   (3/n)      (3/n)      (4/n)     - -
long     8+8n   -   8+8n   12+8n
    long   8+8n     -     8+8n 12+8n    14+8n      12+8n      16+8n     - -
  (2/2n)   - (2/2n) (3/2n)
                (2/2n)     -   (2/2n) (3/2n)   (3/2n)    (3/2n)    (4/2n)     - -
 
instr size d(An,ix)+  xxx.W      xxx.L      d(PC)      d(PC,ix)*
JMP - 14(3/0)    10(2/0)    12(3/0)   10(2/0)    14(3/0)
JSR - 22(2/2)    18(2/2)    20(3/2)   18(2/2)    22(2/2)
LEA - 12(2/0)    8(2/0)    12(3/0)   8(2/0)    12(2/0)
PEA - 20(2/2)    16(2/2)    20(3/2)   16(2/2)    20(2/2)
MOVEM word   18+4n      16+4n      20+4n     16+4n      18+4n
M->R (4+n/0)    (4+n/0)    (5+n/0)   (4+n/0)    (4+n/0)
long   18+8n      16+8n      20+8n     16+8n      18+8n
(4+2n/0)  (4+2n/0)  (5+2n/0) (4+2n/0)  (4+2n/0)
MOVEM word   14+4n      12+4n      16+4n     - -
R->M   (3/n)      (3/n)      (4/n)     - -
long   14+8n      12+8n      16+8n     - -
  (3/2n)    (3/2n)    (4/2n)     - -


n is the number of registers to move
n is the number of registers to move
Line 409: Line 507:
   execution time
   execution time
</syntaxhighlight>
</syntaxhighlight>


=Multi-precision instructions=
=Multi-precision instructions=
Line 422: Line 519:


ADDX byte,word 4(1/0) 18(3/1)
ADDX byte,word 4(1/0) 18(3/1)
  long 8(1/0) 30(5/2)
  long 8(1/0) 30(5/2)
CMPM byte,word   - 12(3/0)
CMPM byte,word   - 12(3/0)
  long   - 20(5/0)
  long   - 20(5/0)
SUBX byte,word 4(1/0) 18(3/1)
SUBX byte,word 4(1/0) 18(3/1)
  long 8(1/0) 30(5/2)
  long 8(1/0) 30(5/2)
ABCD   byte 6(1/0) 18(3/1)
ABCD   byte 6(1/0) 18(3/1)
SBCD   byte 6(1/0) 18(3/1)
SBCD   byte 6(1/0) 18(3/1)
</syntaxhighlight>
</syntaxhighlight>


=Miscellaneous instructions=
=Miscellaneous instructions=
Line 440: Line 536:
calculation where indicated.
calculation where indicated.


instruction size register memory
instruction size register memory


ANDI to CCR byte 20(3/0)   -
ANDI to CCR byte 20(3/0)   -
ANDI to SR word 20(3/0)   -
ANDI to SR word 20(3/0)   -
CHK - 10(1/0) +   -
CHK - 10(1/0) +   -
EORI to CCR byte 20(3/0)   -
EORI to CCR byte 20(3/0)   -
EORI to SR word 20(3/0)   -
EORI to SR word 20(3/0)   -
ORI to CCR byte 20(3/0)   -
ORI to CCR byte 20(3/0)   -
ORI to SR word 20(3/0)   -
ORI to SR word 20(3/0)   -
MOVE from SR -   6(1/0) 8(1/1)+
MOVE from SR -   6(1/0) 8(1/1)+
MOVE to CCR - 12(1/0) 12(1/0)+
MOVE to CCR - 12(1/0) 12(1/0)+
MOVE to SR - 12(1/0) 12(1/0)+
MOVE to SR - 12(1/0) 12(1/0)+
EXG -   6(1/0)   -
EXG -   6(1/0)   -
EXT word   4(1/0)   -
EXT word   4(1/0)   -
long   4(1/0)   -
long   4(1/0)   -
LINK - 16(2/2)   -
LINK - 16(2/2)   -
MOVE from USP -   4(1/0)   -
MOVE from USP -   4(1/0)   -
MOVE to USP -   4(1/0)   -
MOVE to USP -   4(1/0)   -
NOP -   4(1/0)   -
NOP -   4(1/0)   -
RESET - 132(1/0)   -
RESET - 132(1/0)   -
RTE - 20(5/0)   -
RTE - 20(5/0)   -
RTR - 20(5/0)   -
RTR - 20(5/0)   -
RTS - 16(4/0)   -
RTS - 16(4/0)   -
STOP -   4(0/0)   -
STOP -   4(0/0)   -
SWAP -   4(1/0)   -
SWAP -   4(1/0)   -
TRAPV (No Trap) -   4(1/0)   -
TRAPV (No Trap) -   4(1/0)   -
UNLK - 12(3/0)   -
UNLK - 12(3/0)   -


+ add effective address calculation time
+ add effective address calculation time
</syntaxhighlight>
</syntaxhighlight>


=Move Peripheral instructions=
=Move Peripheral instructions=
Line 477: Line 572:
instruction size register->memory memory->register
instruction size register->memory memory->register


MOVEP word 16(2/2) 16(4/0)
MOVEP word 16(2/2) 16(4/0)
long 24(2/4) 24(6/0)
long 24(2/4) 24(6/0)
</syntaxhighlight>
</syntaxhighlight>


=Exception processing=
=Exception processing=
Line 489: Line 583:
fetch and the fetch of the first two instruction words of the handler routine.
fetch and the fetch of the first two instruction words of the handler routine.


exception periods
exception periods


address error 50(4/7)
address error 50(4/7)
bus error 50(4/7)
bus error 50(4/7)
CHK instruction (trap taken) 44(5/3)+
CHK instruction (trap taken) 44(5/3)+
Divide by Zero 42(5/3)
Divide by Zero 42(5/3)
illegal instruction 34(4/3)
illegal instruction 34(4/3)
interrupt 44(5/3)*
interrupt 44(5/3)*
privilege violation 34(4/3)
privilege violation 34(4/3)
        _____
_____
RESET ** 40(6/0)
RESET ** 40(6/0)
trace 34(4/3)
trace 34(4/3)
TRAP instruction 38(4/3)
TRAP instruction 38(4/3)
TRAPV instruction (trap taken) 34(4/3)
TRAPV instruction (trap taken) 34(4/3)


Line 507: Line 601:
* the interrupt acknowledge cycle is assumed to take four
* the interrupt acknowledge cycle is assumed to take four
  clock periods
  clock periods
                                      _____    ____
                                    _____    ____
      ** indicates the time from when RESET and HALT are first
** indicates the time from when RESET and HALT are first
  sampled as negated to when instruction execution starts
  sampled as negated to when instruction execution starts
</syntaxhighlight>
</syntaxhighlight>

Latest revision as of 16:44, 25 November 2018

Mirrored information from [oldwww.nvg.ntnu.no]

The number of bus read and write cycles are shown in parenthesis as (r/w). Any other cycles are internal.

In the following tables, the headings have the following meanings:

  • An : Address register operand
  • Dn : Data register operand
  • ea : Operand specified by an effective address
  • M : Memory effective address operand

To get the real execution time, multiply the total cycles count by 83.33ns (1/12MHz). An example is given in each section.

The vertical blank lasts exactly 40 lines * 384 pixels * 2 cycles per pixel = 30720 cycles (2.56ms).

See optimization.

Effective address operand calculation

This table lists the number of clock periods required to compute an instruction's effective address. It includes fetching of any extension words, the address computation, and fetching of the memory operand.

Syntax Adressing mode B,W L
Dn Data register direct 0(0/0) 0(0/0)
An Address register direct 0(0/0) 0(0/0)
(An) Address register indirect 4(1/0) 8(2/0)
(An)+ Address register indirect, post inc. 4(1/0) 8(2/0)
-(An) Address register indirect, pre dec. 6(1/0) 10(2/0)
d(An) Address register indirect, displacement 8(2/0) 12(3/0)
d(An,ix) Address register indirect, index 10(2/0) 14(3/0)
xxx.w Absolute short 8(2/0) 12(3/0)
xxx.l Absolute long 12(3/0) 16(4/0)
d(PC) PC with displacement 8(2/0) 12(3/0)
d(PC,ix) PC with index 10(2/0) 14(3/0)
#xxx Immediate 4(1/0) 8(2/0)

Notes:

  • Pre-dec is slower than post-inc
  • There are no write cycles involved in processing the effective address
  • The size of the index register (ix) does not affect execution time

Move instructions

These following two tables indicate the number of clock periods for the move instruction. This data includes instruction fetch, operand reads, and operand writes.

Byte and word

Example: move.b (a0)+,$10201D (Byte (An)+ to xxx.L) takes 20 cycles.

  Dn An (An) (An)+ -(An) d(An) d(An,ix) xxx.W xxx.L
Dn 4(1/0) 4(1/0) 8(1/1) 8(1/1) 8(1/1) 12(2/1) 14(2/1) 12(2/1) 16(3/1)
An 4(1/0) 4(1/0) 8(1/1) 8(1/1) 8(1/1) 12(2/1) 14(2/1) 12(2/1) 16(3/1)
(An) 8(2/0) 8(2/0) 12(2/1) 12(2/1) 12(2/1) 16(3/1) 18(3/1) 16(3/1) 20(4/1)
(An)+ 8(2/0) 8(2/0) 12(2/1) 12(2/1) 12(2/1) 16(3/1) 18(3/1) 16(3/1) 20(4/1)
-(An) 10(2/0) 10(2/0) 14(2/1) 14(2/1) 14(2/1) 18(3/1) 20(4/1) 18(3/1) 22(4/1)
d(An) 12(3/0) 12(3/0) 16(3/1) 16(3/1) 16(3/1) 20(4/1) 22(4/1) 20(4/1) 24(5/1)
d(An,ix) 14(3/0) 14(3/0) 18(3/1) 18(3/1) 18(3/1) 22(4/1) 24(4/1) 22(4/1) 26(5/1)
xxx.W 12(3/0) 12(3/0) 16(3/1) 16(3/1) 16(3/1) 20(4/1) 22(4/1) 20(4/1) 24(5/1)
xxx.L 16(4/0) 16(4/0) 20(4/1) 20(4/1) 20(4/1) 24(5/1) 26(5/1) 24(5/1) 28(6/1)
d(PC) 12(3/0) 12(3/0) 16(3/1) 16(3/1) 16(3/1) 20(4/1) 22(4/1) 20(4/1) 24(5/1)
d(PC,ix) 14(3/0) 14(3/0) 18(3/1) 18(3/1) 18(3/1) 22(4/1) 24(4/1) 22(4/1) 26(5/1)
#xxx 8(2/0) 8(2/0) 12(2/1) 12(2/1) 12(2/1) 16(3/1) 18(3/1) 16(3/1) 20(4/1)

The size of the index register (ix) does not affect execution time.

Long

Example: move.l $05012C,4(a1,d0) (Long xxx.L to d(An,ix)) takes 34 cycles.

  Dn An (An) (An)+ -(An) d(An) d(An,ix) xxx.W xxx.L
Dn 4(1/0) 4(1/0) 12(1/2) 12(1/2) 12(1/2) 16(2/2) 18(2/2) 16(2/2) 20(3/2)
An 4(1/0) 4(1/0) 12(1/2) 12(1/2) 12(1/2) 16(2/2) 18(2/2) 16(2/2) 20(3/2)
(An) 12(3/0) 12(3/0) 20(3/2) 20(3/2) 20(3/2) 24(4/2) 26(4/2) 24(4/2) 28(5/2)
(An)+ 12(3/0) 12(3/0) 20(3/2) 20(3/2) 20(3/2) 24(4/2) 26(4/2) 24(4/2) 28(5/2)
-(An) 14(3/0) 14(3/0) 22(3/2) 22(3/2) 22(3/2) 26(4/2) 28(4/2) 26(4/2) 30(5/2)
d(An) 16(4/0) 16(4/0) 24(4/2) 24(4/2) 24(4/2) 28(5/2) 30(5/2) 28(5/2) 32(6/2)
d(An,ix) 18(4/0) 18(4/0) 26(4/2) 26(4/2) 26(4/2) 30(5/2) 32(5/2) 30(5/2) 34(6/2)
xxx.W 16(4/0) 16(4/0) 24(4/2) 24(4/2) 24(4/2) 28(5/2) 30(5/2) 28(5/2) 32(6/2)
xxx.L 20(5/0) 20(5/0) 28(5/2) 28(5/2) 28(5/2) 32(6/2) 34(6/2) 32(6/2) 36(7/2)
d(PC) 16(4/0) 16(4/0) 24(4/2) 24(4/2) 24(4/2) 28(5/2) 30(5/2) 28(5/2) 32(5/2)
d(PC,ix) 18(4/0) 18(4/0) 26(4/2) 26(4/2) 26(4/2) 30(5/2) 32(5/2) 30(5/2) 34(6/2)
#xxx 12(3/0) 12(3/0) 20(3/2) 20(3/2) 20(3/2) 24(4/2) 26(4/2) 24(4/2) 28(5/2)

The size of the index register (ix) does not affect execution time.

Standard instructions

Example: add.w d3,a7 (Word ea Dn + An) takes 8 cycles.

The number of clock periods shown in this table indicates the time required to perform the operations, store the results and read the next instruction. The total number of clock periods must be added respectively to those of the effective address calculation where indicated (+).

  Size <ea>,An * <ea>,Dn Dn,<M>
ADD B,W 8(1/0)+ 4(1/0)+ 8(1/1)+
L 6(1/0)+** 6(1/0)+** 12(1/2)+
AND B,W - 4(1/0)+ 8(1/1)+
L - 6(1/0)+** 12(1/2)+
CMP B,W 6(1/0)+ 4(1/0)+ -
L 6(1/0)+ 6(1/0)+ -
DIVS - - 158(1/0)+ -
DIVU - - 140(1/0)+ -
EOR B,W - 4(1/0) *** 8(1/1) +
L - 8(1/0) *** 12(1/2) +
MULS - - 70(1/0)+* -
MULU - - 70(1/0)+* -
OR B,W - 4(1/0) +** 8(1/1) +
L - 6(1/0) +** 12(1/2) +
SUB B,W 8(1/0)+ 4(1/0)+ 8(1/1)+
L 6(1/0)+** 6(1/0)+** 12(1/2)+ 
notes:	+ Add effective address calculation time
	^ Word or long only
	* Indicates maximum value
       ** The base time of six clock periods is increased to eight		
	  if the effective address mode is register direct or 
	  immediate (effective address time should also be added)
      *** Only available effective address mode is data register direct
	  
	DIVS,DIVU - The divide algorithm used by the MC68000 provides less
		    than 10% difference between the best and the worst case
		    timings.
	MULS,MULU - The multiply algorithm requires 38+2n clocks where
		    n is defined as:
		MULU: n = the number of ones in the <ea>
		MULS: n = concatenate the <ea> with a zero as the LSB;
			  n is the resultant number of 10 or 01 patterns
			  in the 17-bit source; i.e., worst case happens
			  when the source is $5555

Immediate instructions

The number of clock periods periods shown in this table includes the time to fetch immediate operands, perform the operations, store the results and read the next operation. The total number of clock periods must be added respectively to those of the effective address calculation where indicated (+).

  Size #,Dn #,An #,M
ADDI B,W 8(2/0) - 12(2/1)+
L 16(3/0) - 20(3/2)+
ADDQ B,W 4(1/0) 8(1/0)* 12(1/2)+
L 8(1/0) 8(1/0) 12(1/2)+
ANDI B,W 8(2/0) - 12(1/2)+
L 16(3/0) - 20(3/1)+
CMPI B,W 8(2/0) - 8(2/0)+
L 14(3/0) - 12(3/1)+
EORI B,W 8(2/0) - 12(2/1)+
L 16(3/0) - 20(3/2)+
MOVEQ L 4(1/0) - -
ORI B,W 8(2/0) - 12(2/1)+
L 16(3/0) - 20(3/2)+
SUBI B,W 8(2/0) - 12(2/1)+
L 16(3/0) - 20(3/2)+
SUBQ B,W 4(1/0) 8(1/0)* 8(1/1)+
L 8(1/0) 8(1/0) 12(1/2)+ 
	+ Add effective address calculation time
	* word only

Single operand instructions

This table indicates the number of clock periods for the single operand
instructions. The number of clock periods and the number of read and write cycles
must be added respectively to those of the effective address calculation
where indicated.

instruction	size		register	 memory

CLR			byte,word	4(1/0)		 8(1/1) +
			  long		6(1/0)		12(1/2) +
NBCD		  byte		6(1/0)		 8(1/1) +
NEG			byte,word	4(1/0)		 8(1/1) +
			  long		6(1/0)		12(1/2) +
NEGX		byte,word	4(1/0)		 8(1/1) +
			  long		6(1/0)		12(1/2) +
NOT			byte,word	4(1/0)		 8(1/1) +
			  long		6(1/0)		12(1/2) +
Scc			byte,false	4(1/0)		 8(1/1) +
			byte,true	6(1/0)		 8(1/1) +
TAS #		  byte		4(1/0)		10(1/1) +
TST			byte,word	4(1/0)		 4(1/0) +
			  long		4(1/0)		 4(1/0) +

	+ add effective address calculation time
        # This instruction should never be used on the Amiga as its invisiable
          read/write cycle can disrupt system DMA.

Shift and rotate instructions

This table indicates the number of clock periods for the shift and rotate
instructions. The number of clock periods and the number of read and write
cycles must be added respectively to those of the effective address
calculation where indicated.

instruction	size		register	memory

ASR,ASL		byte,word	6+2n(1/0)	8(1/1) +
			  long		8+2n(1/0)	  -
LSR,LSL		byte,word	6+2n(1/0)	8(1/1) +
			  long		8+2n(1/0)	  -
ROR,ROL		byte,word	6+2n(1/0)	8(1/1) +
			  long		8+2n(1/0)	  -
ROXR,ROXL	byte,word	6+2n(1/0)	8(1/1) +
			  long		8+2n(1/0)	  -

	+ add effective address calculation time
	n is the shift or rotate count

Bit manipulation instructions

This table indicates the number of clock periods required for the bit
manipulation instructions. The number of clock periods and the number of read and 
write cycles must be added respectively to those of the effective address
calculation where indicated. Dynamic: register, static: immediate.

instruction  size            dynamic                 static
                        register   memory       register   memory	
BCHG         byte          -       8(1/1) +        -       12(2/1) +
             long        8(1/0) *    -          12(2/0) *     -
BCLR         byte          -       8(1/1) +        -       12(2/1) +
             long       10(1/0) *    -          14(2/0) *     -
BSET         byte          -       8(1/1) +        -       12(2/1) +
             long        8(1/0) *    -          12(2/0) *     -
BTST         byte          -  	   4(1/0) +        -        8(2/0) +
             long        6(1/0)      -          10(2/0)       -

	+ add effective address calculation time
	* indicates maximum value

Conditional instructions

Mnemonic Displacement Branch taken Not taken
Bcc byte 10(2/0) 8(1/0)
word 10(2/0) 12(1/0)
BRA byte 10(2/0)
word 10(2/0)
BSR byte 18(2/2)
word 18(2/2)
DBcc cc true 12(2/0)
cc false 10(2/0) 14(3/0)

JMP, JSR, LEA, PEA and MOVEM instructions

This Table indicates the number of clock periods required for the jump,
jump-to-subroutine, load effective address, push effective address and
move multiple registers instructions.

instr	size    (An)		(An)+		-(An)	 d(An)		d(An,ix)+   xxx.W      xxx.L      d(PC)      d(PC,ix)*
JMP     -	    8(2/0)	     -		      -    10(2/0)		 14(3/0)    10(2/0)    12(3/0)	  10(2/0)    14(3/0)
JSR     -	   16(2/2)	     -		      -	   18(2/2)		 22(2/2)    18(2/2)    20(3/2)	  18(2/2)    22(2/2)
LEA     -	    4(1/0)	     -		      -	    8(2/0)		 12(2/0)     8(2/0)    12(3/0)	   8(2/0)    12(2/0)
PEA     -	   12(1/2)	     -		      -	   16(2/2)		 20(2/2)    16(2/2)    20(3/2)	  16(2/2)    20(2/2)
MOVEM   word     12+4n       12+4n	      -      16+4n		   18+4n      16+4n      20+4n	    16+4n      18+4n
M->R           (3+n/0)	   (3+n/0)	      -	   (4+n/0)		 (4+n/0)    (4+n/0)    (5+n/0)	  (4+n/0)    (4+n/0)
	    long     12+8n	     12+8n	      -	     16+8n		   18+8n      16+8n      20+8n	    16+8n      18+8n
		      (3+2n/0)    (3+2n/0)	      -   (4+2n/0)		(4+2n/0)   (4+2n/0)   (5+2n/0)	 (4+2n/0)   (4+2n/0)
MOVEM	word	  8+4n	     -		     8+4n	 12+4n  	   14+4n      12+4n      16+4n	    -			-
R->M		     (2/n)	     -		    (2/n)	 (3/n)		   (3/n)      (3/n)      (4/n)	    -			-
	    long	  8+8n	     -		     8+8n	 12+8n  	   14+8n      12+8n      16+8n	    -			-
                (2/2n)	     -		   (2/2n)	(3/2n)		  (3/2n)     (3/2n)     (4/2n)	    -			-

n is the number of registers to move
* is the size of the index register (ix) does not affect the instruction's
  execution time

Multi-precision instructions

This table indicates the number of clock periods for the multi-precision
instructions. The number of clock periods includes the time to fetch both
operands, perform the operations, store the results and read the next 
instructions.

instruction	size		op Dn,Dn	op M,M

ADDX		byte,word	4(1/0)		18(3/1)
			  long		8(1/0)		30(5/2)
CMPM		byte,word	  -			12(3/0)
			  long		  -			20(5/0)
SUBX		byte,word	4(1/0)		18(3/1)
			  long		8(1/0)		30(5/2)
ABCD		  byte		6(1/0)		18(3/1)
SBCD		  byte		6(1/0)		18(3/1)

Miscellaneous instructions

This table indicates the number of clock periods for the following 
miscellaneous instructions. The number of clock periods and plus the number
of read and write cycles must be added to those of the effective address
calculation where indicated.

instruction		size	register	memory

ANDI to CCR		byte	 20(3/0)	   -
ANDI to SR		word	 20(3/0)	   -
CHK				 -		 10(1/0) +	   -
EORI to CCR		byte	 20(3/0)	   -
EORI to SR		word	 20(3/0)	   -
ORI to CCR		byte	 20(3/0)	   -
ORI to SR		word	 20(3/0)	   -
MOVE from SR	 -	 	  6(1/0)	 8(1/1)+
MOVE to CCR	 	 -		 12(1/0)	12(1/0)+
MOVE to SR	 	 -		 12(1/0)	12(1/0)+
EXG				 -		  6(1/0)	   -
EXT				word	  4(1/0)	   -
				long	  4(1/0)	   -
LINK		 	 -		 16(2/2)	   -
MOVE from USP	 -		  4(1/0)	   -
MOVE to USP	 	 -		  4(1/0)	   -
NOP				 -		  4(1/0)	   -
RESET			 -		132(1/0)	   -
RTE				 -		 20(5/0)	   -
RTR				 -		 20(5/0)	   -
RTS				 -		 16(4/0)	   -
STOP		 	 -		  4(0/0)	   -
SWAP		 	 -		  4(1/0)	   -
TRAPV (No Trap)	 -		  4(1/0)	   -
UNLK		 	 -		 12(3/0)	   -

	+ add effective address calculation time

Move Peripheral instructions

instruction	size	register->memory	memory->register

MOVEP		word	16(2/2)				16(4/0)	
			long	24(2/4)				24(6/0)

Exception processing

This table indicates the number of clock periods for exception processing.
The number of clock periods includes the time for all stacking, the vector
fetch and the fetch of the first two instruction words of the handler routine.

	exception						periods

	address error					50(4/7)
	bus error						50(4/7)
	CHK instruction (trap taken)	44(5/3)+
	Divide by Zero					42(5/3)
	illegal instruction				34(4/3)
	interrupt						44(5/3)*
	privilege violation				34(4/3)
	_____
	RESET **						40(6/0)
	trace							34(4/3)
	TRAP instruction				38(4/3)
	TRAPV instruction (trap taken)	34(4/3)

	+ add effective address calculation time
	* the interrupt acknowledge cycle is assumed to take four
	  clock periods
                                    _____     ____
	** indicates the time from when RESET and HALT are first
	  sampled as negated to when instruction execution starts
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