MSP430F5239: Shared RESET PIN.

Hello Rei,

The RST pin is not open drain. Adding the external reset device could potentially interfere with proper programming of the device, especially in SBW mode. I would recommend some sort of jumper when programming to disconnect the external reset IC, especially in prototype boards to see if the IC will effect programming. I have seen customers use external reset ICs just fine, but I have also seen programming issues due to them.

For this specific MSP430 device, i'm not sure of an external RESET IC is necessary. This device has a watchdog timer as well as a robust internal SVS/SVM that can be used to reset the device due to failing voltage. There are also numerous ways to reset the device via SW if needed.

Hello,Jace-san.

Thank you for your reply.

I understood that it's better not adding the external reset device to same line.

but I want to monitor the external voltage with reset device.

Can I connect as follows for monitoring and reset?

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JTAG RST pin--- RSTDVCC/SBWTDIO

reset device RST pin--- RST/NMI

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I think that it is possible from datasheet .(P.19 NOTE:)

http://www.ti.com/lit/ds/slas897b/slas897b.pdf

Regards,

Rei.