> >Doing a reasonably complete job of testing a board can take time, especi=
ally
> >without automated tools.  This is something you want done at the
> >manufacturer's labor rate, not yours.
>=20
> Except that you will generally be able to diagnose faults _much_ faster t=
han
> the manufacturer, since you know the design inside out, and can do things=
 like
> tweak firmware to help find faults, which is why testing at least an init=
ial
> batch yourself is useful to optimise the test procedure and be able to do
> some 'if it does this, check parts x,y,z first' type guidance to save the
> manufacturer time, and hence your money.
> And to debug any test software of course - a test system failure can put =
a major
> spanner in the works for everyone's schedule.

The other trick, if using a chip like a PIC24 or any others with JTAG is to=
 use the JTAG interface for the board test at the assembly house - doesn't =
need any software in the chip if you do it right (AIUI, haven't tried doing=
 it), so your IP doesn't go AWOL on a 'lost' chip.

I got this from talking with a supplier of JTAG test gear, at the previousl=
y mentioned show I went to. It seems they have libraries of components that=
 can be interfaced through JTAG, and help the board house set up the test p=
rogram on the JTAG unit.

OK, you lose a handful of pins to the JTAG interface, but these can be brou=
ght out to pads for fitting resistors to indicator LEDs after the JTAG test=
, so the pins don't necessarily need to be lost permanently, you always nee=
d some indicators.
--=20
Scanned by iCritical.

--=20
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