• State
  • Locked Locked
  • Replies 2 replies
  • Subscribers 79 subscribers
  • Views 578 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

CC430 UART errors

Avi W
Expert 1345 points

Other Parts Discussed in Thread: CC430F5137

Hello,

I'm using CC430F5137 with uart at 9600 bps.

Most (more than 80%) of the input data is OK, but from time to time I got BAD readings from the Rx line.
The data is 100% valid & tested with logic.
Below is my initialization (taken from Ti examples for 9600...

  UCA0CTL1 |= UCSWRST;                      // **Put state machine in reset**
  UCA0CTL1 |= UCSSEL_1;                     // CLK = ACLK
  UCA0BR0 = 0x03;                           // 32k/9600 - 3.41
  UCA0BR1 = 0x00;                           //
  UCA0MCTL = 0x06;                          // Modulation
  UCA0CTL1 &= ~UCSWRST;                     // **Initialize USCI state machine**
  UCA0IE |= UCRXIE;                // Enable USCI_A0 TX/RX interrupt

It seems like replication of:
http://e2e.ti.com/support/microcontrollers/msp430/f/166/t/34240.aspx?pi283121=1

Besides blaming the oscillator any ideas?   

  • 0
    Guru 227245 points

    Maybe your baudrate is wrong?

    How do you setup the clock source for the USCI? You are using 32768kHz (which is usually working, but introduces a quite large bit timing error, as 32768 doesn't divide well by 9600). If you don't use a crystal but the internal REFO, this adds some more error. And your PC side might be off too. Worst case, this all sums up on certain bit patterns to an error that leads to garbage (missed bits, framing errors etc.).

**Attention** This is a public forum