Doubt on the STM6600 use

[Andrea Verdecchia]

Posted on February 16, 2017 at 23:54

I want to use the STM6600 controller to manage the power ON/OFF of my microcontroller system. In the specific I want:

- Turn ON the system simply pushing a button.

- Turn OFF the system simply pushing the same button.

- Force the power OFF pushing and holding the same button.

I read at pg. 5 on the STM6600

/external-link.jspa?url=http%3A%2F%2Fwww.st.com%2Fcontent%2Fccc%2Fresource%2Ftechnical%2Fdocument%2Fdatasheet%2F1f%2F9e%2F3b%2F43%2Fec%2F04%2F44%2F71%2FCD00226957.pdf%2Ffiles%2FCD00226957.pdf%2Fjcr%3Acontent%2Ftranslations%2Fen.CD00226957.pdf

that

'By a long push of one button (&sharpPB) or two buttons (&sharpPB and &sharpSR) either a reset is asserted or power for the application is disabled depending on the option used.'

It says that pushing one button (&sharpPB) OR two button

(&sharpPB and &sharpSR) I can disable the main power

Then at pg. 10 it says

'A short push of the push-button during normal operation can initiate an interrupt through

debounced &sharpINT output (see Figure 14) and a long push of &sharpPB and &sharpSR simultaneously can

either assert reset output &sharpRST (see Figure 18) or deassert the EN or &sharpEN output (see

Figure 19) based on the option used.'

In this case it says that, to disable the EN signal, I have NECESSARILY to push two button: the &sharpPB and the &sharpSR simultaneously.

Now I'm a bit confused. If I want use only one push button to have the behaviour described above, I have to connect to ground permanently the &sharpSR input of the STM6600 controller?

null

[David Ashman]

Hi Andrea. I too am confused by the ST data sheet. I think it is VERY misleading regarding the long switch push description. I filed a case with ST tech support regarding the information but have not heard back.

I did however come across app note AN3271. It shows how to use one switch to perform the on/off functions as well as hung processor power down from a long press. I've white wired my STM6600CS25DM6F and it does work very well. Hope this helps.