ST7FLITE29, RESET not working

delser9 · ‎2006-03-07

Posted on March 07, 2006 at 11:46

mustapha_jellouli · ‎2005-08-11

Posted on August 12, 2005 at 05:20

Dear Al

I already have this kind of problem on one of my application. But I completely change my hardware. I use a voltage regulator with shut down. Then when the voltage decrease below 2v the regulator stop regule and then it start proprely each time.

I talk with ST support about this problem, they told that we must have a 20us

Also the pin PA6 must be at high level during reset (see description pin on the data sheet).

Regards

Mustapha

delser9 · ‎2005-08-12

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 · ‎2005-08-12

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 · ‎2005-08-14

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 · ‎2005-08-15

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 · ‎2006-02-28

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 · ‎2006-03-07

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