• State
  • Locked Locked
  • Replies 4 replies
  • Subscribers 80 subscribers
  • Views 2487 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.

baud rate calculation for usci in i2c

GURU MOORTHY
Expert 2425 points

Other Parts Discussed in Thread: MSP430G2553

hi,

can any one help me out in calculating UCB0BR0 value and UCB0BR1 value for usci as i2c. i am using smclk as clock and want 100khz scl.

  • 0
    Guru 25210 points

    One would assume that it depends on (1) which MSP430 device you are using and (2) what speed your SMCLK is set to.

    (1) because different MSP430 families have slightly different I2C peripherals

    (2) SMCLK can be almost any value depending on what your clock source is and how you set up the SMCLK.

    As a general rule, I direct people with questions like this to the User's Guide for the MSP device they are using. It will have a whole chapter on using the UART in I2C mode and will give you the equations you need to calculate this yourself fairly easily.

    Now, if you come back and say "they user's guide said to do this, but I don't understand x/y/z", then that is a more useful thing to do because (a) you already learned something, and (b) we feel like you at least made some effort to earn our valuable time in helping you.

  • 0 in reply to Brian Boorman
    Expert 2425 points

    hi,

    I use msp430g2553 and smclk=1Mhz and I need 100kHz SCL.

  • 0
    Guru 227245 points

    It’s a very simple equation:

    1,000,000 / x = 100,000

    X is the value for UCB0BR (low byte to UCB0BR0, high-byte to UCB0BR1)
    It should be obvious after reading the baudrate generation part of the USCI chapter in the users guide.

**Attention** This is a public forum