I2C troubleshooting

Dan Henry <usenet@danlhenry.com> wrote:
> Bob Stephens <stephensyomamadigital@earthlink.net> wrote:

> >I2C has a mode where you can stretch the clock to accomodate slower
> >devices. IIRC the slave holds off the bus by stretching the low period of
> >SCL. There is a timeout feature to prevent hanging up the bus indefinitely.

> Several non-exhaustive examinations (i.e. skims) of Philips' I2C spec
> (version 2.0 December 1998) does not indicate what that timeout is.
> Where and how is the timeout quantified?

Standard I2C has no timeout, SMB has.
-- 
Uwe Bonnes                bon@elektron.ikp.physik.tu-darmstadt.de

Institut fuer Kernphysik  Schlossgartenstrasse 9  64289 Darmstadt
--------- Tel. 06151 162516 -------- Fax. 06151 164321 ----------

Uwe Bonnes wrote:
> Dan Henry <usenet@danlhenry.com> wrote:
> 
>>Bob Stephens <stephensyomamadigital@earthlink.net> wrote:
> 
> 
>>>I2C has a mode where you can stretch the clock to accomodate slower
>>>devices. IIRC the slave holds off the bus by stretching the low period of
>>>SCL. There is a timeout feature to prevent hanging up the bus indefinitely.
> 
> 
>>Several non-exhaustive examinations (i.e. skims) of Philips' I2C spec
>>(version 2.0 December 1998) does not indicate what that timeout is.
>>Where and how is the timeout quantified?
> 
> 
> Standard I2C has no timeout, SMB has.
Right. My bad. I use the SMBus on a SiLabs micro and that's what I was 
thinking of. The data sheet claims that SMB is I2C 'compatible'. Iwonder 
if there is a definitive list of what the differences are?

Bob