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

2010-08-28 Thread Henry Chen
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

2010-08-28 Thread Jack Hickish
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

[casper] GPIO input/output select on ROACH

2010-08-27 Thread Jack Hickish
Hi all, I've been playing around with the GPIO on a ROACH, and just to ease my curiosity, can anyone tell me what the pins that are driven by the gpiox_oe_n blocks actually *do*? Anyone with an answer will surely save me many sleepless nights of idle wondering... Cheers, Jack