ST7FLITE29, RESET not working

[delser9]

Posted on March 07, 2006 at 11:46

ST7FLITE29, RESET not working

[delser9]

Posted on August 12, 2005 at 10:39

Hello Mustapha

we are actually considering a redesign as you suggested. But what do you mean with PA6 must be high? Could you tell me where this is written in the datasheet? Just to be sure: we are talking about ST7FLITE2.

Thanks

Al

[mustapha_jellouli]

Posted on August 12, 2005 at 12:03

Dear Al,

Yes I talk about ST7FLITE2, you can see the warning about PA6 page 7 on the data sheet August 2003.

Regards

Mustapha

[wolfgang2399]

Posted on August 15, 2005 at 05:26

... or on page 13 (Rev.3.0, October 2004):

Caution: During normal operation the ICCCLK pin

 

must be pulled- up, internally or externally (external

 

pull-up of 10k mandatory in noisy environment).

 

This is to avoid entering ICC mode unexpectedly

 

during a reset. In the application, even if

 

the pin is configured as output, any reset will put it

 

back in input pull-up.

Regards

WoRo

[delser9]

Posted on August 15, 2005 at 13:38

Dear Mustapha and WoRo

Thanks for your help!

It seems to work now, after we added the pull up. (But we still don't understand why the RESET pin does not work in that case...)

Thanks again and best regards

Al

[y2399]

Posted on March 01, 2006 at 06:57

Hi all,

I'm upping this old post because, I'm experiencing exactly the same problem than Al_Capone with an ST7FLITE05M6 microcontroller. I'm using LVD with medium thresold voltage and sometime, at power up, the microntroller don't start and keep stuck. The only way to restart the MCU is to pull down Vdd to GND during several seconds and this problem don't occuer at all power-up sequence. The problem is that I did not respect the recommendation of ST7LITE0 datasheet (Rev 3.0 october 2004) on page 14:

''During normal operation the ICCCLK pin must be pulled- up, internally or externally (external pull-up of 10k mandatory in noisy environment). This is to avoid entering ICC mode unexpectedly during a reset. In the application, even if the pin is configured as output, any reset will put it back in input pull-up.''

But I don't know if the MCU can enter ICC mode only at power up reset or power up and power down reset are concerned.

The problem is that on my board, ICCCLK pin (PA6) cannot be pulled up, so i'm asked 2 question:

1. if MCU enter in ICC mode, will the hardware watchdog will work and generate an MCU reset to leave ICC mode and restart the software ?

2. is it possible to configure dynamically PA6 pin in order to configure it in pull-up mode in normal time and to leave it floating before each port reading?

Thanks a lot in advance for your help.

[laurent239955_stm1]

Posted on March 07, 2006 at 11:46

Hi,

Power down reset is not concerned, but both cold and hot reset are concerned, i.e cold at power-up and hot reset with the CPU still power supplied.

1.Watchdog is not used in ICC mode.

2.There is no way to configure PA6 to avoid this behaviour because it is the configuration during reset which is taken into account.

Best regards

Laurent