Hi Team MSPFR,
This following info in slau550 makes no sense to me. It says that “A floating condition on the TCK and TMS pins increases the probability of the device entering JTAG mode. TI recommends external termination of the pins to avoid this problem. Add a 47-kΩ pullup resistor and a 1-nF pulldown capacitor on TCK and TMS. Stronger termination might be needed depending on noise in the system.”
Since these devices default to SBW (& not 4Wire JTAG).. no termination should be required on the 4Wire JTAG pins, right?
IMO.. it makes no sense to recommend “Add a 47-kΩ pullup resistor and a 1-nF pulldown capacitor on TCK and TMS”.. is this really referring to pins TCK/TMS.. or is it referring to the nRST/TEST pins (since nRST does have a recommend for 47K/1.1nF)? What about TDI? We also do not want it floating.
Also.. if we set the JTAG 4Wire pins to GPIO mode as Out/Low.. there should be no danger of inadvertent JTAG entry thru these 4Wire JTAG pins, right?
That is the recommend in the MSP430FR59941 datasheet (https://www.ti.com/lit/ds/symlink/msp430fr59941.pdf ) for unused pins.. "The JTAG pins are shared with general-purpose I/O function (PJ.x). If not being used, these should be switched to port function, output direction. When used as JTAG pins, these pins should remain open."..
Thanks, Merril
