hi,

thanks for the answers.
because board area is very limited i was looking for a possibility to do
a (kind of) quick and dirty address data-bus extention on demand where i
additionally can write hardware peripherals in the fpga connected to
this bus but also extend the bus through the fpga if desired (as i said,
kind of "dirty")...

regards



Jonathan Bromley wrote:
> On Sat, 24 Nov 2007 12:56:34 +0100, joe <[email protected]> wrote:
>
>> i would like to use a small fpga (or cpld) on a pcb to make direct
>> bidirectional connections between pins.
>> basically it should act like a programmable "cable".
>> is this kind of application possible using programmable logic?
>
> Not with a conventional CPLD. You would need to know enough
> about the signal flow to control the CPLD's output buffers.
>
> There are plenty of bidi switch devices around (QuickSwitch
> and suchlike). It might be a good idea to build a crosspoint
> matrix of such switches, and then use a small CPLD to control
> the enables.
>
> Lattice have a really interesting product that might suit
> your needs:
> http://www.latticesemi.com/products/...ct/ispgdx2.cfm
>
> I have no idea about price, availability and development tools
> for those parts.