Closed GoogleCodeExporter closed 9 years ago
Original comment by philip.l...@gmail.com
on 15 Feb 2011 at 6:23
Hi,
Can you provide a bit more info on the platform that you are using, i.e. which
epoc core design and what devices are attached to the port? Switching between
SPI and I2C has always been very tricky on the 1611, and the errata is full
with I2C issues.
If the I2CEN was not disabled, your proposed change would effectively send a
START condition. Did you check if the I2CSTT is indeed the culprit? I.e. did
all successful modifications of I2CTCTL include a set I2CSTT? I wonder if this
is again some timing issue or the internal I2C state machine somehow gets
confused by the previous SPI signaling...
Vlado
Original comment by vlado.handziski
on 16 Feb 2011 at 2:18
No problem. The Epic core version I'm using is the 11-28-2007 version that has
the flash and radio on the same bus. The only I2C device on the I2C bus is my
light sensor, a Rohm BH1721FVC. I'm using a new board that I created, and I
have attached the schematic.
I know that setting I2CTCTL to the particular value 0x01 isn't required, and
that that value wasn't chosen because of the I2CSTT bit. I believe writing 0x00
will work. I tried some variations to determine if the value mattered, and I
think I found some that didn't work (closer to 0xFF), but I didn't try too
hard. After looking at the errata sheet it does seem that just writing I2CTCTL
resets the I2C state machine which takes care of the problem, but I don't know
for sure.
Brad
PS. The origin of writing 0x01 is because the U0TCTL register is reset to 0x01,
and I found the U0TCTL register as the problem before I realized it was the
same as I2CTCTL.
Original comment by brad...@gmail.com
on 17 Feb 2011 at 11:48
Attachments:
Patch applied as temp. fix in rev 5508. I still can not recreate the problem on
my hw though.
Vlado
Original comment by vlado.handziski
on 12 Mar 2011 at 12:40
Since I had this issue I've made more of the hemera boards and some have this
problem and some don't. I have no idea why.
Original comment by brad...@gmail.com
on 12 Aug 2011 at 8:07
Original issue reported on code.google.com by
brad...@gmail.com
on 4 Feb 2011 at 6:09