S12XE SCI Error Rate

[Luna_Maverick]

Hello,
I am a developer developing with XET256 MCU.

I am considering whether I should communicate using SCI or SPI.

I want to use SCI.

I want the SCI Baud Rate to use 500kbps.

Below are the PLL clock settings I set.
Internal bus clock: 32Mhz
VC0 clock frequency: 64Mhz
Reference divider: 1
PLL multiplication factor: 2
PLL post divider: 1

and IREN : 0

I looked at the MC9S12XEP100 Reference Manual Covers MC9S12XE Family datasheet.

I have Table 20-16 on page 742 of the datasheet. I would like to know the formula for calculating the Error (%) value in Baud Rates (Example: Bus Clock = 25 MHz).

Luna_Maverick_0-1715671496521.png

Please tell me how to get Baud Rates Error.

And please tell me what the error rate is for 500kbps in my specs.

Luna_Maverick_1-1715671400359.png

thanks.

[lama · Accepted solution]

Hi,

1) Attached...contains also required calculations and formula for UART -  I think it is usable without additional words. (Only change green cells, and button Summarize results)

2) https://community.nxp.com/t5/S12-MagniV-Microcontrollers/S12X-PLL-Filter-Calculator/ta-p/1125313

Best regards,

Ladislav