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Re: [Xylo-SDR] Xylo


I asked the question because I didn't see a schematic
in the first ByteBlaster data sheet I looked at.  However,
I did find data sheets for both the ByteBlasterMV and
the ByteBlaster II on line that did have schematics.
the MV schematic is based on a 74HC244 so would
be easy to copy and would work with 3.3 or 5V FPGA's.
The ByteBlaster II schematic just shows generic buffers
but opening the one at work, I saw about 26 small
3 legged SMT devices, so probably using transistors
to make a buffer to go between the parallel port signals
and the 1.8, 2.5, 3.3 or 5V signals required for the FPGA.

Guess I'll stick to the 74HC244 version,  although $25 for the
KNJN version is a very good deal for those with more money
than time.

John


At 12:37 AM 12/14/2005, Leon Heller wrote:


----- Original Message -----
From: "John Kolb" <jlkolb@jlkolb.cts.com>
To: "Xylo-SDR Discussion" <xylo-sdr@lists.ae5k.us>
Sent: Wednesday, December 14, 2005 4:07 AM
Subject: Re: [Xylo-SDR] Xylo


> At 10:06 AM 12/13/2005, you wrote:
>>A USB2 port to talk to the PC, a I2C port to talk to the A/D and D/A
>>chips, and a bunch of I/O pins, what else do we need?
>
> I was thinking today about a FPGA PCB design, and thinking that
> if the header pins come out the bottom, as on the Sylo, rather than
> the top, they could either be stuffed with straight pins to plug into a
> carrier PCB, or stuffed with right angle IDC connectors to allow cables
> to plug into the board while on the carrier.  Only thing I would have
> done differently would be to have used 20 pin headers instead of 14,
> to allow an HP 165x series logic analyer pod to plug in for debugging.
> Of course the flying leads can be used with any size connector.
>
> Has Altera published the design of the parallel port programming
> cable so that we could build our own? Or is there a cheap way
> to buy one?

It's quite easy to build one's own from Altera's schematic, I have details
on my web site. I've designed an improved version using SM. A PCB isn't
essential

I'm not sure if mine is suitable for the Cyclone devices, though. It should
work if VccIO is 3.3V, which it will be on my proposed Cyclone II board.
Altera hasn't published details of the current ByteBlaster.

Leon
--
Leon Heller, G1HSM
leon.heller@bulldoghome.com
http://www.geocities.com/leon_heller

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