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Message
From: "Damon Brantley" <brantley@m...>
Date: Thu, 24 Apr 2003 21:03:01 -0500
Subject: Re: [openrisc] Re:Getting the size down
I tried the changes you made and they worked for me. The utilization after
synthesis was 73%.
Regards,
Damon
At 02:22 PM 4/24/2003 -0700, you wrote:
>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@m...>
>To: <openrisc@o...>
>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@m...>
>> >To: <openrisc@o...>
>> >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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