I'm using the UART0 and SMBUS0 hardware on a Silabs F340. Both drivers seem to work well when operating while the other is not. But, when I have the UART0 sending chars and the SMBUS0 reading data from a IIC eeprom, the UART0 characters turn into garbage.

Here are the active interrupts and register banks on my system are as follows:

Source    Register Bank
UART0     2
UART1     2
INT0      (unconfigured?) (Using the Silabs TCP/IP stack)
INT1      1 (PCA timer producing a regular system tick of 10ms)
PCA       1
Timer3    unconfigured (IIC timeout detection)
SMBUS0    unconfigured

 

All interrupts are low priority.

It doesn't make sense to me that I get garbage out of the UART. I would expect dropped characters if my system was being interrupted too often. If I change the UART0 to high priority, I still get garbage characters. The IIC data always looks fine.

So, does anyone have any ideas how to troubleshoot an interrupt collision problems like this one seems to be? The Silabs debugger is of some help, and I have a good digital oscilloscope probing the problem, but I don't know how to reliably trigger the situation.

Thanks,

--David