This post is a copy from here
Hello everyone,
We’re facing an issue with SENT communication software example using the S32K344 microcontroller and the CDD_SENT driver from the NXP RTD. When configuring the Tick Length above 7 µs, the SENT communication fails.
Context:
- The SENT receiver uses the FLEXIO module, which includes two 16-bit timers.
- At Tick Lengths above 7 µs, messages are lost, likely due to a timer overflow during sync pulse measurement (56 ticks).
- Our client manually modified the TIMDEC register from 000b to 101b (FLEXIO clock divided by 256), which allowed communication to work with a Tick Length of 90 µs, though with occasional corrupted messages.
Questions:
- Is manually modifying the TIMDEC register in the RTD a recommended approach to solve this issue? Is there a way to configure the FLEXIO clock divider properly using the S32DS Config Tool, rather than editing the RTD code manually?
- What do you recommend to configure FLEXIO for SENT communication with Tick Lengths greater than 7 µs?
- In the Config Tool, the Tick Length configuration shows a valid range from 3 µs to 5000 µs. Is it normal to allow values as high as 5000 µs?
- In the RTD for I2C, we noticed that the FLEXIO timer decrement mode can be configured directly via the Config Tool using the following options:
Is it expected that such configuration options are not available in the SENT RTD? Even after manually changing this parameter in the SENT RTD, the client still experiences corrupted frames (1 out of 4).
Could this be related to how the timer counts high vs. low states? Has anyone encountered similar behavior?
Any insights or shared experiences would be greatly appreciated!
Thanks in advance,
Best regards,
Imad EL MASOUDI
Hi @RaduBraga ,
FLEXIO SENT driver does not support clock divider that is supported in I2C (with clock divider is written to TIMDEC).
I tried to run SENT with 9us is configured for Sent Tick Length:
FLEXIO SENT will receive frame from SENT device that is configured by the tool Kexplorer with some parameters as below:
with description about Sync low and sync high as below:
In my case:
Sync low = 5 x 9 = 45
Sync high = 51 x 9 = 459
It worked.
Please let them try this with their device.
Best regards,
Nhi