[hpsdr] [OZY] Initial OZY Schematic Posted For Review andComments- May 10, 2006

[Philip Covington]

Hi Phil,

On 5/11/06, Phil Harman <pvharman at arach.net.au> wrote:
> ***** High Performance Software Defined Radio Discussion List *****
>
> Hi Phil,
>
> Very nice start to the Ozy board.  A few suggestions;
>
> 1. Protect the USB input lines against static etc. I've used SMS05T1 before
> and they work fine.

It looks like the SMS05T1's capacitance is way too high for USB 2.0.
I checked TI and they don't appear to make any USB 2.0 overvoltage
clamps like they do for USB 1.1

> 2. Apologioes for being a scratched record on this.... but is it OK that the
> I2C pins from the FX2 pass through the FPGA and then onto the bus.  I
> suggest that the I2C pins go directly to the bus and the FPGA sits on the
> I2C like any other device. We can always add an I2C master/slave in the FPGA
> at a later date.

I need to make that addition.  I meant to do it initially but forgot
about it obviously.  Right now I don't show the I2C pins going to the
ATLAS bus (they appear to just go to the FPGA).

> 3. Can you bring the I2C lines out to a header on the edge of the board for
> adding external I/O

Can do.

> 4. 8 LED's are  fine with me.
>
> 5. For (protected) user inputs  can you add an 8 bit 74LCX541 with a
> connector on the board edge to take PTT, dot, dash, GPS 10k/1pps etc
>
> 6. For user outputs perhaps an open collector driver such as an UNL2003AD to
> a connector on the board edge

This will depend on other things like whether we put SRAM on the OZY
board and how much IO I actually end up with.  It might be a better
idea just to limit the off board IO to the ATLAS lines and design a
plug-in IO board with protected ins/outs, etc... to handle the things
we need.

Oh Gosh... WHERE'S THE EXCEDRIN BOTTLE?

> 7. A reset signal from the Ozy board that is available on the Atlas bus..

In the process of being added... MCP130...

> Appologies of some of these have already been covered,  I have a massive
> backlog of mail to catch up with.
>
> 73's Phil...VK6APH

73 de Phil N8VB

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