external 32KHz clock

David Falk said:

Nothing happens until the clock is actived.

What should happen? What do you expect to happen? What did you try?

By default, the msot MSPs are configured to activate a crystal on XT1, some with shared GPIO on the XT pins are configured to have GPIO by default.

However, if you want to send an external square wave signal to XIN, the XT1 module must be configured for bypass mode.

In any case, every MSP will start without external clock source, as the default clock source after reset is the always available internal DCO. On 4x family, the (by default active) FLL will without external reference signal adjus tthe DCO down to lowest setting, but even then the MSP will run, just on a low MCLK speed of a few 100 kHz.

David Falk said:

How can I do that

THe clock module and how it works and how it is programmed is completely described in the 4x family users guide, FLL+ module section.

Hi,

For testing our MSP board we use an external tester wich one provides an 32kHz clock on XT1 Input pin. On usual use of our board, an external sensor board (ASIC), provides also an 32kHz clock on XT1 Input pin.

1) connect the tester interface or ASIC

2) MSP check the value on AD bus

3) MSP enter into test mode if the value is 5hex, no interrupt must disturb or halt the testing mode. if the value is different as 5hex go on point 5)

4) when test is finnished

5) MSP go on normal mode

I tried to use the LPM3 mode of the MSP, because it use the external clock, but the MSP do anyway a reset (the program begin at main program).