[Coco] 6809 FPGA

Dave Philipsen dave at davebiz.com
Fri Sep 11 02:34:36 EDT 2015


Yes, serious.  Go for it!  It's got more RAM than the EP2C5T.

With the EP2C5T when you use the 6809 BASIC and the full VGA 
implementation there is only maybe 1K or 2K RAM leftover.  With your 
board there will be beaucoup!



Dave



On 9/11/2015 12:42 AM, Bill Nobel wrote:
>> Well I know the AS6C4008-55PCN will work because I've got it running on two different FPGA projects right now.  Maximum speed that I can run the CPU core is 16.67 MHz with those.  But, when I used the internal memory I could go the full 25 MHz no problem.  While you're waiting on the Mouser shipment you should give the internal memory a try even if you only try 4K at first.  Grant's code enables it with this:
>>
>> internalRam1DataOut when n_internalRam1CS= '0' else
>>
>> and:
>>
>> internalRam1DataOut when n_internalRam1CS= '0' else
>>
>> Just comment out these:
>>
>> sramData when n_externalRamCS= '0' else
>>
>> and:
>>
>> n_externalRamCS <= '0' when cpuAddress(15 downto 13) = "001" or cpuAddress(15 downto 13) = "010" or cpuAddress(15 downto 13) = "011" or cpuAddress(15 downto 13) = "100" else '1';
>>
> Are you serious,  I did’t think I could use any of the internal ram Grant said in his post.  I thought that was unique to the ep2c5t144c8n he was using (learned more again)
>
> Bill Nobel
>
>
>


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