Dear Gene,
I also had some problems using a crystal with that dsp, my solution was to
use a clock oscillator instead (to pin 142, pin 143 xtal to ground through
0.1uF cap) , now the dsp boots up the 100% times, i know that for production
boards is a complete diferent case because of cost issues but just wanted to
let you know, cheers
Sergio
>From: "Gene-eng"
>To:
>Subject: [adsp] Re: FW: Debug problem for ADSP-21262
>Date: Mon, 8 May 2006 13:44:24 -0400
>
>Rongxi,
>
>Please elaborate when you say "It failed to start if there were two 18pF
>capacitors connected between its crystal and ground." What crystal
>frequency and what capacitor values have you found to work without failure?
>
>We have been having problems with ADSP-21262's in production boards
>occasionally failing to boot (VDSP JTAG debugger can't even connect).
We
>changed crystal capacitors to 18pf (as well as better 1.2V core supply
>improvements) and the failure rate is lower but still not 0%.
>
>Thanks,
>Gene
>
> > From: "phychem" p...@hit.edu.cn
> > Date: Sun May 7, 2006 6:22am(PDT)
> > Subject: Re: FW: Debug problem for ADSP-21262
> >
> > Hi!
> > Thank you Sergio and Todd. I tried overnight and solved the problem. I
> > removed the two 22pF capacitors from the DSP crystal and it works
> > fine...The same problem happened a few days ago when we were debugging a
> > board of ADuC7020.It failed to start if there were two 18pF capacitors
> > connected between its crystal and ground. It is quite strange rite?
> >
> > Regards,
> > Rongxi
