I2C Stops After 8th SCL Pulse

Jason Ku

Other Parts Discussed in Thread: MSP430F5632, SYSBIOS

I have several devices connected to a MSP430F5632 microcontroller, and I am trying to set up I2C communications using TI-RTOS with both USCIB0 and USCIB1. USCIB0 seems to be working okay, but USCIC1 will stop after the first 8 SCL pulses, and the line will be held low forever. If I pause the execution, it shows that it is stuck in the while loop of this HWI:

__interrupt Void ti_sysbios_family_msp430_Hwi45(Void)
{
while(1){};
}

If I run the I2C communication over USCIB1 without TI-RTOS (driverlib + USCI_B1_VECTOR interrupts), the communication seems to work fine. The oscilliscope shows the following signals:

over 9 years ago

0 Gilbert Rodriguez III over 9 years ago

TI__Intellectual 2275 points

Hi Jason,

Are you using CCS? If so, have you checked ROV to see if any exceptions are being thrown?

Gilbert

0 Jason Ku over 9 years ago in reply to Gilbert Rodriguez III

Intellectual 265 points

Hi Gilbert,

Yes, I am using CCS, but I don't see any relevant exception messages in the logs. Here are the csv logs from a session with only I2CB0 (which works), and a session with only I2CB1.

Jason

0636.Live Session - I2CB0.txt

7356.Live Session - I2CB1.txt

0 Gilbert Rodriguez III over 9 years ago in reply to Jason Ku

TI__Intellectual 2275 points

You most likely haven't defined the Hwi instance for the USCIB1 interrupt. If you look at your cfg file, you can find one being made for USCIB0. It should look something similar to "halHwi.create(55, &I2CUSCIB_hwiIntFxn", hwiParams);" You will need to create a similar one with 45 instead of 55.

Gilbert

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I2C Stops After 8th SCL Pulse