Re: FPGA/CPLD different approach

Hello!

Bil Herd wrote:

> I did a quick fitting on some opencores and found that the PIO’s and
> support chips probably fir in the CPLD’s and that the processors
> probably didn’t.

That's generally what is to be expected. However, there are support
chips that will definitely not fit into a CPLD, for example the RIOT
(due to the RAM and/or ROM). Also the CIA is actually quite a complex
chip and you will need a really big CPLD to handle it. Of course, also
VIC, VDC and TED chips will reauire a FPGA as well.

> I have a question for anyone that is interested in using FPGA/CPLD
> emulated parts: How important is it that the PCB of a drop in
> replacement stay strictly in the foot print of a 40/48 pin chip or is
> the PCB okay to be wider than .6” once its .3-.4” above the socket it’s
> inserted into?

For me it's okay if it's larger, but it wuld be much better if it were
not because someone might want to stick two such "chips" next to each
other. But it's not critical.

Regards,
Michau.


> 
>  
> 
> Bil
> 
>  
> 
> *From:*owner-cbm-hackers@musoftware.de
> <mailto:owner-cbm-hackers@musoftware.de>
> [mailto:owner-cbm-hackers@musoftware.de
> <mailto:owner-cbm-hackers@musoftware.de>] *On Behalf Of *Ed Spittles
> *Sent:* Tuesday, August 27, 2013 4:13 PM
> *To:* cbm-hackers@musoftware.de <mailto:cbm-hackers@musoftware.de>
> *Subject:* Re: FPGA/CPLD different approach
> 
>  
> 
> For some purposes OHO's GOP board might be a better fit than the GODIL -
> it's smaller, got fewer pins, but has a 512kByte SRAM on board..
> 
> http://www.trenz-electronic.de/products/fpga-boards/oho-elektronik.html
> 
> http://shop.trenz-electronic.de/catalog/default.php?cPath=1_48_137
> 
>  
> 
> (For simple designs there are CPLD variations, but as noted that's not
> big enough for a 6502-like CPU, or for ROM or RAM.)
> 
>  
> 
> As noted elsewhere, these boards have 5V level converters, crystals, and
> on-board EEPROM for configuration.
> 
>  
> 
> Cheers
> 
> Ed
> 
>  
> 
>  
> 
> On 27 August 2013 11:34, Ingo Korb <ml@akana.de <mailto:ml@akana.de>> wrote:
> 
> Bil Herd <bherd@mercury-cg.com <mailto:bherd@mercury-cg.com>> writes:
> 
>> I have gone through some test fitting but haven't really checked out
>> GODIL, for instance can they program the VCC and Ground pins or do
>> they have to physically configure?
> 
> They can be freely configured using jumpers, but as Didier noted the
> pinning of those headers is a bit weird. IIRC the DIL pin alternates
> between the left and right side of the header and the other pin
> alternates between 5V and GND for each row, so you can select GND and 5V
> for any DIL pin by setting the jumper either horizontally or
> vertically.
> 
> 
>> I suspect that to keep the cost
>> down that the PCB might be wider than the .6" DIP but didn’t yet
>> research if that’s a show stopper.
> 
> It's much wider and longer - the board is 33.5 mm x 74.3 mm, the DIL
> interface at the bottom appears to be centered. The overall height
> including the DIL pins is ~20 mm.
> 
> -ik
> 
> 
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> 
>  
> 


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