Re: [Gumstix-users] Avoiding conflicts on Overo connectors

[Dave H. <dhy...@gm...>]

Hi Tom,

On Mon, Dec 21, 2009 at 6:21 AM, comrex <har...@gm...> wrote:
>
> Sorry to beat a dead horse here, but to give you an example why that's not
> enough info:
>
> I want to design my motherboard with a DMA-capable interface to the
> expansion bus. OK, so the hardware pinout gives me the basic signals, but
> not the irq, dma request line, wait pin etc. These are found on alternate
> functions of other pins that happen to be available on the connector.
>
> But which ones do I choose? I have to guess because Gumstix has not laid out
> exactly what they use for things like their wireless interface, boot prom,
> etc.

What's wrong  with looking at the kernel source to determine which DMA
lines are available or otherwise used? The boot prom is built into the
processor, and is fully documented in the datasheet.

> This is just an example. If I want to utilize alternate pins for SPI, McBSP,
> I2C etc I'm in the same boat.

Use the source. It's all there. If the pin is used, it will be
mentioned in the source.

> Not they they don't have their own support issues, but a competing product
> from Compulab has a real hardware user's guide with detailed explanation of
> what's connected where on their boards.

Yep - it would be nice to at least describe which signals are used by
the on-motherboard peripherals.

-- 
Dave Hylands
Shuswap, BC, Canada
http://www.DaveHylands.com/