processor clock cycle per instructions

faz wrote:
> 
> Can u pls suggest the method or formula to calculate number of
> processor clock cycles for each instructions ?It will be greatful to
> knew this as i have referred the Intel data sheets which includes.I am
> eager to knew how they r calculating it.

I can.  But u hasn't posted here for years.  Read the chip
specification.  Study the spelling.  Put blanks after punctuation. 
Look up the proper spelling for 'pls', 'r'.  Learn not to confuse
posts for no reason.

-- 
 Chuck F (cbfalconer at maineline dot net)
   <http://cbfalconer.home.att.net>
   Try the download section.



-- 
Posted via a free Usenet account from http://www.teranews.com

On Tue, 04 Dec 2007 00:07:27 -0800, faz wrote:

> On Dec 4, 12:39 pm, Christof Klaiber <christof.klai...@merath-
> maschinen.de> wrote:
>> Am Mon, 03 Dec 2007 21:18:36 -0800 schrieb faz:
>>
>> > Can u pls suggest the method or formula to calculate number of
>> > processor clock cycles for each instructions ?It will be greatful to
>> > knew this as i have referred the Intel data sheets which includes.I
>> > am eager to knew how they r calculating it.
>>
>> They don't calculate it, they design the cpu accordingly.
>>
>> /Christof
> 
> Suppose if i have the CPU design then to verify clock cycles per
> instructions...I have to run the instruction am i right??I am thinking
> of some short cut method without running each instruction since it is my
> design i knew all the parameters...Is there any method available??

On the one hand, the operations a CPU needs to undertake to execute an 
instruction are built in pretty early in the CPU design; this isn't some 
superficial thing like paint color.

On the other hand, while in a non-pipelined CPU an instruction's 
execution time would be fixed by the operations, in pipelined CPUs a 
particular instruction's total time is not only longer than it's average 
cycle time, but both the total time and the 'average' cycle time are 
heavily dependent on the instructions that are executed before and after 
the instruction in question.

-- 
Tim Wescott
Control systems and communications consulting
http://www.wescottdesign.com

Need to learn how to apply control theory in your embedded system?
"Applied Control Theory for Embedded Systems" by Tim Wescott
Elsevier/Newnes, http://www.wescottdesign.com/actfes/actfes.html

faz wrote:

> Hai all,
> 
> Can u pls suggest the method or formula to calculate number of
> processor clock cycles for each instructions ?It will be greatful to
> knew this as i have referred the Intel data sheets which includes.I am
> eager to knew how they r calculating it.

I have seen processors that figure from several instructions per cycle  down
to several cycles per instruction. The information is all in the data
manual for the processor concerned. If you need to be accurate you have no
short-cut to counting each type of instruction, multiplying by the cycles
each takes and totallising for all instruction types.

If you just want an approximate average then look at the mix of instructions
you use and how long they take. Whilst not a very precise method it will
get you a feel for the ballpark.

-- 
********************************************************************
Paul E. Bennett...............<email://Paul_E.Bennett@topmail.co.uk>
Forth based HIDECS Consultancy
Mob: +44 (0)7811-639972
Tel: +44 (0)1235-811095
Going Forth Safely ..... EBA. www.electric-boat-association.org.uk..
********************************************************************

faz wrote:

> On Dec 4, 12:39 pm, Christof Klaiber <christof.klai...@merath-
> maschinen.de> wrote:
> 
>>Am Mon, 03 Dec 2007 21:18:36 -0800 schrieb faz:
>>
>>
>>>Can u pls suggest the method or formula to calculate number of
>>>processor clock cycles for each instructions ?It will be greatful to
>>>knew this as i have referred the Intel data sheets which includes.I am
>>>eager to knew how they r calculating it.
>>
>>They don't calculate it, they design the cpu accordingly.
>>
>>/Christof
> 
> 
> Suppose if i have the CPU deisgn then to verify clock cycles per
> instructions...I have to run the instruction am i right??I am thinking
> of some short cut method without running each instruction since it is
> my design i knew all the parameters...Is there any method available??

What are you actually trying to do ?

If it is your design, then the short-cut is to simply look at your 
design notes, and it will, of course, be clearly detailed there :)

Of course, if you designed a CPU, you WILL need to run each instruction,
in order to confirm it DOES work as you hoped.

I'm curious: How can you design a CPU, and NOT know the cycles per 
instruction ?

=jg