From: "Richard Everett"
Subject: Re: What important issue about interfacing ISA I must focus on?(open-collector,tri-state,totem-pole,open-drain)
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Date: Sun, 29 Sep 2002 20:17:07 GMT
NNTP-Posting-Date: Sun, 29 Sep 2002 16:17:07 EDT
He could go to opencores.org and check out the free pci core there.
"Nico Coesel" wrote in message
> email@example.com (Ru-Chin Tsai) wrote:
> >I want to interface FPGA device with ISA. I have no any design
> >experience about interface LPT, ISA, PCI. I fear to damage PC
> >motherboard or FPGA if I directly connect pins between FPGA and ISA
> >without concerning the output
> >type(open-collector,tri-state,totem-pole,open-drain). Can every
> >experienced designer give me the design issue and suggestions?
> Start with PCI, buy a ready-to-go core and you will be okay.
> There are 2 reasons to stay away from ISA:
> -ISA is not standard. Every PC chipset has it's own way of handling
> ISA which translates in to small differences in timing.
> -ISA is considered obsolete. If you want to turn this project into a
> product, you'll need PCI.
> >Does I must concern the ISA digital output type from
> >motherboard(signal send to FPGA)? Will anything damage the FPGA
> If you use a 5V tolerant device, you'll be okay. Check if your FPGA
> can handle a shorted pin. Connecting 2 outputs to each won't hurt
> much. In most cases it will prevent the PC from booting so you will
> see there is something wrong soon enough.
> >Oppositely,how do I decide to deal with the output from FPGA as which
> >type output(open-collector,tri-state,totem-pole,open-drain), and then
> >connect to ISA input pin from damaging the motherboard?
> Checking your design with an experimental setup (i.e. simulate the
> address bus with dip-switches or use an old motherboard) is a good
> Reply to nico@nctdevpuntnl (punt=.)