Re: [Gumstix-users] SPI CS pins on reset

[Conor O'R. <con...@sc...>]

>> The pulldowns are 100uA (equivalent to 18k at 1.8V). The second line
>> sounds like a massive gotcha. On reset, connecting my SPI slaves
>> straight to CS1 and CS0 would result in both peripherals being
>> selected. I can't imagine this is a good thing!
>
> If the SPI clock isn't toggling, no data will be clocked into the
> slaves.  No big deal there.

OK, that's fair enough. Generally I'd be concerned that MISO could be
asserted by both and result in bus contention. I didn't know that
McSPI could default to a slave - thanks, I'll go and check that.

> My big problems were:
>
>  - I didn't have a free GPIO to Enable/Disable the level shifters.

Ah. I didn't think of that for some reason. I have quite a few GPIOs
spare and can use any of those in a pinch. That sorts me out then :-)
I'll do the same as you though and get into U-Boot early and configure
the lines. I'm generally uncomfortable leaving inputs floating or in
odd states. I'm sure it's similar for the DuoVero.

Thanks,

Conor.