Re: [avrdude-dev] Safer timing in par_txrx()?

[axel]

hallo,
mybe I can help with some messurements.
http://hoxel.no-ip.org/pio/basteln/avr/isoprog/mess.html
Ciao Axel

Jan-Hinnerk Reichert schrieb:

> Hi,
>
> after the latest post from address@hidden, I had a look at the way 
> PPI-programmers work.
>
> Currently par_txrx() works like this:
> - read MISO
> - set MOSI
> - put SCK high
> - put SCK low
>
> The target chip reads MOSI on the rising edge of SCK with some 
> setup-time and it shifts MISO out at the falling edge of SCK.
>
> So, I believe that we would gain some immunity to delays, if we change 
> the order to:
> - set MOSI
> - read MISO
> - put SCK high
> - put SCK low
>
> Any comments on this?
> Is it really safe to change it?
> Should we do it before the release?
>
> Cheers
> Jan-Hinnerk
>
>
>
> _______________________________________________
> avrdude-dev mailing list
> address@hidden
> http://mail.nongnu.org/mailman/listinfo/avrdude-dev
>
>