Which Nordic MCU's, if any, support odd parity for UART?

[chris_h]

Hi,

I have a project requirement to interface with HART, which is a protocol that specifies odd parity for UART.   I recently found out UART odd parity isn't supported on my nRF52840.

I have read through the attached forum https://devzone.nordicsemi.com/f/nordic-q-a/45754/uart-does-not-support-odd-parity where the engineer said none of the Nordic MCU's support odd parity.  

However looking through the SoC headers in NCS v3.1.1, UART_CFG_PARITY_ODD is present on the nRF52833, nRF82820, nRF5340, and nRF54 series, which conflicts with the forum post.  Furthermore the forum post is over 7 years old and new hardware variants exist that didn't before. 

Can a Nordic engineer please confirm if any Nordic MCU's currently support odd parity for UART, and if so, specifically which models?  

Thanks in advance!

Chris

[Vidar Berg]

Hi Chris,

Yes, we odd parity is supported on newer variants and models. The other nRF52 variants you listed were launched after the nRF52840, and it looks like the answer in the linked post has simply become outdated. For new designs, you should probably focus on the nRF54L series, which generally provides the best value and performance. 

(https://docs.nordicsemi.com/bundle/ps_nrf54L15/page/uarte.html)

Best regards,

Vidar

[chris_h]

Hi Vidar,

Thank you for your response.  I would prefer to stick to the nRF52 family for compatibility / availability and am looking at the nRF52833 as the best alternative.

I have confirmed in the nRF52833 product specification registers that UART supports odd parity (see attached), but the main features on section 6.32 are a bit misleading. 

For peace of mind and before I commit to a big hardware change, can you please confirm this too? 

Kind regards,

Chris

[Vidar Berg]

Hi Chris,

Yes, I can confirm that odd parity is supported on this part. I haven't noticed that the feature list at the beginning of the UARTE chapters has not been updated to reflect this until you pointed it out now.

Kind regards,

Vidar

[chris_h]

Thank you for your help Vidar!