MSPM0G3107-Q1: LIN communication baud rate tolerance

David Daggett

Tool/software:

Our customer is requesting a baud rate tolerance of <= 1% because of slave to slave communication. They don’t trust the controller if we don’t use baud rate synchronization, because the tolerance of the base clock is >1% and they believe the PLL will also increase the tolerance.

To determine this, the customer has some questions about tolerances for the M0G3107, could you try to answer it?

Tolerance of the PLL
For LIN we don’t use baud rate synchronization, our main clock is 80MHz and our baud rate is 19200. We have slave to slave communication in the car which needs a high precision clock. Which accuracy in % could be reached for our system?

Thanks,
David

over 1 year ago

0 Helic Chi over 1 year ago

TI__Mastermind 25807 points

David Daggett said:
Tolerance of the PLL

SYSPLL won't increase the clock accuracy, and SYSPLL accuracy depends on its clock source/reference.

David Daggett said:
a baud rate tolerance of <= 1%

This mean need a 1% accuracy clock source.

David Daggett said:
For LIN we don’t use baud rate synchronization, our main clock is 80MHz and our baud rate is 19200. We have slave to slave communication in the car which needs a high precision clock. Which accuracy in % could be reached for our system?

For UART/LIN, with 1% is recommended.

SYSOSC with Rosc's accuracy can be below 1%, but it's not full temperature range.

https://www.ti.com/lit/ds/symlink/mspm0g3107-q1.pdf

7.9.1 System Oscillator (SYSOSC)

But, the external osc is still recommended, which has <100ppm accuracy.

Arm-based microcontrollers

Arm-based microcontrollers forum

MSPM0G3107-Q1: LIN communication baud rate tolerance