I2C Hang issue in LPC2364

neethugprem · ‎10-28-2016

Hi All,

We are using I2C1,and I2C0 in LPC 2364 for connecting 4 devices.

RTC and EEPROM are connected to I2C1 which is mentioned as not open drain in datasheet.

The controller and all the interfaces were working properly without any issue when we programmed it initially.

But gradually the performance of the controller is decaying, as the I2C1 is hanging and not responding.

Now we observed that the I2C1 SDA pin (P0.0-Pin 46) is not even toggling as a normal GPIO. And seems like the pin is damaged.

Is there any issue if more than one devices are connected to the I2C1 bus, as it is not an open drain configuration.?

Is there any issue if internal pull up is enabled?

Is there any thing to be taken care in software level when using an 12C pin which is not in an open drain configuration?

Kindly help me to resolve the issue..

Regards,

Neethu

CarlosCasillas · ‎11-14-2016

Hi, Neethu:

Accordind with AE team, using I2C1 and I2C0, the only difference is I2C0 can support the ability to turn power off to the LPC2300 without causing a problem with other devices on the same I2C bus. While I2C1 cannot support, because if power down, the pull-up resistor changed, this will effect the I2C bus. No other limited required.

For detail description, you can refer to Chapter 21.4 of User Manual.

From your description, the I2C1 start work well, gradually the performance of the controller is decaying, seems the IO port be damaged. Does other board have the same issue? Or is there many plug/unplug operation be take to connect the I2C device? The EDS protecting maybe should be considered.

Hope this will be useful for you.
Best regards!
/Carlos
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neethugprem · ‎11-15-2016

Hi Carols,

Many boards have same issue. We do number of plug and unplug, we also believe that this may be the cause for that.

Thanks for your support.

regards,

Neethu.

CarlosCasillas · ‎11-13-2016

Hi Neethu,

We are internally reviewing your case, in the meantime, you could check the I2C slaves specifications, in order to verify the no-open-operation characteristics, and if the supply voltage (on I2C pins) are the same on all devices.

Hope this information will be useful. I will post an update ASAP.

Best regards!

/Carlos

neethugprem · ‎11-15-2016

Hi Carols,

The supply voltage for both devices connected are same and is 3.3V.

Regards,

Neethu