Re: [Discuss-gnuradio] d'board io - write works, read ?

[Eric Blossom]

On Mon, Feb 21, 2005 at 09:13:41PM -0500, cswiger wrote:
> Gang - Compile/install CVS usrp and gr-usrp - now
> sink.write_io(0,0xBBBB,0xMMMM) toggles bits on the TX daughter board
> A-OK. It reads 0 or 3.3 volts on pins of J50 and J51. No problem.
> 
> Now for reading the pins, all I get is '257' ;)
> 
> Poweroff, exit python. Apply power, start python and type
> 
> >>>from gnuradio import usrp
> usrp: found usrp rev2
> >>>sink = usrp.sink_c(0,64)
> TX d'board A: basic Tx
> TX d'board B: <none>
> >>>sink._write_oe(0,0x0000,0xffff)   # unnecessary but in case, set all
> True                                 # pins inputs
> >>>sink.read_io(0)           # pin is still connected to the meter,
> 257                          # (floating).
> >>>sink.read_io(0)           # pin is connected to 3.3v pin on j47,
> 257                          # verified with meter.
> >>>sink.read_io(0)           # pin is connected to ground.
> 257
> 
> Same results with Rx d'board.
> I don't dare try 5vdc on the io pins without permission ;)
> 
> How can I read a pin now?
> 
> --Chuck

Looks like we've got a problem reading back the contents of any FPGA
register.  Need to figure out when and how we broke this.

Eric