The TI E2E™ design support forums will undergo maintenance from Sept. 28 to Oct. 2. If you need design support during this time, contact your TI representative or open a new support request with our customer support center.

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.

MSP430FR5994: Connection between MSP430FR5994 and TPS3431EVM

Part Number: MSP430FR5994
Other Parts Discussed in Thread: TPS3431, , MSP-FET

Good morning,

In my project I'm evaluating the hardware watchdog timer TPS3431 in order to reset the MSP430FR5994.

I would like to know:

- can directly connect the WDO of the TPS3431 to the RST/NMI pin of the MCU (pin 38 in the 80-pin package)?

- do I need to configure the RST/NMI pin with a specific function?

Thank you very much for your help.

Best regards,

Matteo Colombo

  • Hello Matteo,

    Yes, you can connect the TPS3431 WDO output to the RST/NMI pin of MCU.  The WDO is an open-drain IO so you will need a 1k to 100k pull up resistor as suggested in the datasheet.  A 47Kohm resistor is a typical pull up value recommended for MSP430 MCUs so that will work fine. 

    You do not need to configure the RST/NMI pin on the MCU.  The pin acts as a RESET by default.

    Programming reminder: Keep in mind when programming the MSP430, a programmer (MSP-FET430 for example) will attempt to drive the RST/NMI pin as part of the device programming sequence.  With the TPS3431 connected and powered on, it's output should be in open drain mode and allow the MSP-FET to control the RST/NMI pin normally.  But, should the programmer not recognize the MSP430 (invalid device ID), you may have to temporarily remove the WDO pin during programming.

  •  Thank you very much for you fast reply.

    Best regards,

    Matteo Colombo

**Attention** This is a public forum