Reset & Test pin MSP430G2553

HI, Test has internal weak pull down so can be left floating if no long track are connected to, Is also used for programming so you must route it to an external connector if you wish to use on board programming to.

 Reset again need to meet some timing constraint when used for programming and emulation on SBW connection, I generally suggest to insert a resistor from the rc node to Reset pin.

 Regards

How to determine this timing pararmeter at reset pin

Hi, a capacitor in parallel to a line forever slow down timing, so if capacitor is never directly connected to communication lines slow down doesn't appear.

 My suggestion is to insert a resistor between RC and reset pin for programming like pictured below.

What purpose R2 solves here. Do it helps reset pin to get charge fatser

I think the internal BOR will generate ~400 usec delay, much longer than the external RC on the nRST pin.

I was incorrect. BOR delay is ~2000 usec.

 R2 do nothing when stand alone but isolate the capacitive load from programming signal and clean all issue with programmers.

 I got in the past a lot of programming error, device not connected and similar error, all disappeared forever at any speed.