Re: [casper] GPIO input/output select on ROACH

Hi Jack, The GPIOs on the ROACH are spread across different I/O banks, so they are all at different voltages. To make them all a uniform 3.3V, they go through unidirectional level translators; the gpiox_oe_n signals control the drive directions of these translators. Cheers, Henry On 8/27/2010

Re: [casper] GPIO input/output select on ROACH

Hi Henry, Thanks for that. As it happens I was also wondering why LVCMOS15 outputs (as in the ucf file) managed to be 3V -- should have put two and two together I guess. Thanks Jack On 28 August 2010 17:40, Henry Chen hche...@ssl.berkeley.edu wrote: Hi Jack, The GPIOs on the ROACH are