libftdi Archives

Subject: RE: strange chip select issue

From: "Chaves, Kevin" <kevin.chaves@xxxxxxxxxxxxxxxx>
To: "libftdi@xxxxxxxxxxxxxxxxxxxxxxx" <libftdi@xxxxxxxxxxxxxxxxxxxxxxx>
Date: Tue, 17 Sep 2013 10:51:15 -0700
> 0x80 0x00 0x00 sets all pins low, sets all as inputs. 
> If what I'm thinking makes since and I should go confirm this with my 
> hardware team.
> The reason why the CS start at dbus3 is that maybe in spi mode the ftdi chip 
> uses adbus 0-2 as miso/mosi/clk... 
> 0xX8 would set dbus 3 as anoutput only, while the libmpsse is using dbus 3-7 
> as outputs 0xF8. 
> Hmmm seems wrong otherwise the libmpsse is toggling all the chip select lines.


So after talking to my hardware team, seems this makes a very large difference. 
On the device that works we have a reset line on dbus5 that is disconnected 
currently. On the one that doesn't work we have a reset line on dbus5 that is 
connected. So libFTDI is driving all the lines low and using them as inputs.

Success!

I do have one more question, is it possible to use the MPSSE commands using the 
virtual com port that opens up on windows?

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