MSP430FR6922 TEST Pin Noise Immunity

Mark Ackerson

Other Parts Discussed in Thread: MSP430FR6922

Customer is migrating from MSP430FR6922 RevA to Rev B. Rev B includes improvements to TEST pin noise immunity but does not fix the PORT28 errata according to the latest MSP430FR6922 Device Erratasheet (Rev. F). Customer is considering a 10K external pulldown to reduce TEST pin noise immunity.

Questions:

1. What value resistor would you recommend on the TEST pin that would still allow JTAG functionality? MSP430 JTAG wiki suggests 4.7K.

2. Confirm JTAG would be disabled after 100 usec following a transient event as noted in the MSP430™ Programming With the JTAG Interface (Rev. X)

Anything else you would suggest?

Thanks,

Mark

over 7 years ago

0 Katie Pier over 7 years ago

TI__Guru 68116 points

Hi Mark,

I'm going to look into this but it will probably be tomorrow at least before I have an answer because I need to talk to some experts in the tools teams and research this erratum.

For Port28 - is the customer going to clear the SFRRPCR SYSRSTRE bit? Because if not I don't think that errata would concern them.

Regards,
Katie

0 Mark Ackerson over 7 years ago in reply to Katie Pier

TI__Genius 10190 points

Customer's considering using an RC filter on the TEST pin to minimize any transient noise. What is the fastest speed the TEST pin ever needs to be manipulated during JTAG communications? They will set up the RC time constant to filter accordingly.

Thanks,

Mark

0 Katie Pier over 7 years ago in reply to Mark Ackerson

TI__Guru 68116 points

Hi Mark,

According to our quality team, you really shouldn't need the external pulldown if you are using Rev. B. However, if you want to add an external pulldown in general on any project 10k is ok to still allow programming access.

Regards,
Katie

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MSP430FR6922 TEST Pin Noise Immunity