Re: [openrisc] Re:Getting the size down

["Damjan Lampret" <lampret@opencores.org>]

Damon,

if you update your sources, you will now find two defines that remove MAC
and multiplier. They are called OR1200_MAC_IMPLEMENTED and
OR1200_MULT_IMPLEMENTED. These two defines do probably what you did, except
they are now standard. By default they are both enabled. Note if you want to
have MAC, you also need to enable multiplier.

regards,
Damjan

----- Original Message -----
From: "Damon Brantley" <brantley@mcloudteleco.com>
To: <openrisc@opencores.org>
Sent: Wednesday, April 23, 2003 7:41 PM
Subject: Re: [openrisc] Re:Getting the size down


> I took out the multiplier and it cut the utilization on my gate array from
> 96% to 72%.
> This includes the vga interface I added. With just synthesizing
or1200_top,
> utilization went from 89% to 70%.
> These are just the numbers that xst spits out when the synthesis is done.
> Still it is enough for me
> to push on.
>
> It did take more than a simple removal of the multiplier. My test c
> program, which just bounces a character
> around on the display, acted very flaky with just removing the multiplier
> instantiation.
> I had to chase down the connections to the related modules and def things
> out as needed. Possibly there
> were some dangling outputs that were generating noise.
>
> Regards,
> Damon
>
>
>
>
> At 04:33 PM 4/23/2003 -0700, you wrote:
> >Damon,
> >
> >You can comment (disable) the following assuming you don't need them:
> >OR1200_CFGR_IMPLEMENTED (this one most likely you don't need)
> >OR1200_TT_IMPLEMENTED (do you need tick timer?)
> >OR1200_CASE_DEFAULT (some case defaults will be removed, might confuse
some
> >synthesis tools)
> >
> >If you update your sources from the cvs, then you will also be able to
> >disable implementations of not needed exceptions. For deeply embedded
> >applications running firmware certain exceptions like alignment, illegal
> >instruction and bus error are not needed at all.
> >
> >Also like Michael said you can remove multiplier if you don't needed.
Right
> >now there is no define to disable multiplier. I can add one if there is
> >demand, and even beter is idea of simple small shifting multplier.
> >
> >regards,
> >Damjan
> >
> >----- Original Message -----
> >From: "Damon Brantley" <brantley@mcloudteleco.com>
> >To: <openrisc@opencores.org>
> >Sent: Wednesday, April 23, 2003 4:42 AM
> >Subject: [openrisc] Re:Getting the size down
> >
> >
> >>
> >> Here it is.
> >>
> >> Thanks,
> >> Damon
> >>
> >> >Can you send your or1200_defines.v so I can see if you really
"removed"
> >> >everything possible.
> >> >
> >> >regards,
> >> >Damjan
> >>
> >> >----- Original Message -----
> >> >From: "Damon Brantley" <brantley@m... >
> >> >To: <openrisc@o... >
> >> >Sent: Tuesday, April 22, 2003 7:52 PM
> >> >Subject: [openrisc] Getting the size down
> >>
> >>
> >> >> I am currently working with a board made by Digilent that has a
Spartan
> >> IIe
> >> >> with 300k
> >> >> gates. By removing all the cache and debug logic, the openrisc cpu
uses
> >> >> about 84% of the available space.
> >> >> My last test project,which interfaced with the vga display, pushed
the
> >> >> utilization up to 96%.
> >> >> Are there any other places where I can do some pruning and get the
size
> >> >> down more. To get ucLinux up and
> >> >> running I need at least enough space to add the memory controller to
> >> access
> >> >> some external memory
> >> >> and the UART.
> >> >>
> >> >>
> >
> >
>
>---------------------------------------------------------------------------
-
> >----
> >
> >
> >>
> >>
> >
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