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Subject: Re: Could anyone spare a clue?

From: John Oyler <john.oyler@xxxxxxxxxxxxxx>
To: libftdi@xxxxxxxxxxxxxxxxxxxxxxx
Date: Mon, 23 Aug 2010 10:17:01 -0500

On Aug 21, 2010, at 2:49 PM, Michael Plante wrote:

John Oyler wrote:

Can anyone summarize what needs to be done next to talk to an SPI chip
on the other side? I need to set its registers (I have a detailed
description of how to do this from an SPI standpoint), and read back
I'm picking through the documentation as best I can, but nothing is
really jumping out at me as what I need to do next.

You need to look at AN108, "command processor for MPSSE".  Everything is a
packet of sorts.  Maybe my timing was overly aggressive, but I had to add
functions to resynchronize (done by sending known-bad commands 0xAA and
0xAB, and waiting for *proper* replies, possibly retrying) occasionally.
Not everything about MPSSE is clearly documented, but the SPI aspect should
be straightforward if you're careful to build it up block by block.

Something's screwy. When I look at the chip on the board, it definitely says FT2232D. However according to AN108, this chip only has the inteface/channel A.

When I look at the schematic for this device ( page 23), I'm seeing BCBUS and BDBUS lines going to various things.

Even the schematic lists this as an FT2232D. Am I missing something here?

John O.

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