Cannot exit StandbyMode on RTC alarm

tj2 · ‎2008-03-26

Posted on March 27, 2008 at 06:41

tj2 · ‎2005-10-25

Posted on October 25, 2005 at 11:58

The example is working on the MB393B demo board.

But not on our board. - The CPU never wakes up again and a reset or a logic high on the wake up pin is necessary.

tj2 · ‎2005-10-25

Posted on October 25, 2005 at 13:05

Yet another experiment.

I've tried to source the V18BKP with an external 1.8V source, to see if this could be the problem. But without any luck.

I'm starting to suspect the processor. Could we have received a bad batch of STR710 ICs? Is there a Errata Sheet available for the processor?

tj2 · ‎2005-10-26

Posted on October 27, 2005 at 05:10

Hi Risc

I've send an email to you with the information you requested.

tj2 · ‎2005-10-27

Posted on October 27, 2005 at 09:34

Problem solved!

Due to a silicon bug in device version 3.2 (with A mark) the capacitor connected between V18 and V18vss (pin 58 and 59) must be changed to a 1ÂµF. The bug is fixed in device version 3.3 (with Z mark).

@RISC - Thank you for your great help to solve this problem!

bb2 · ‎2008-03-26

Posted on March 27, 2008 at 06:41

Hi,

Until now we have only received and produced with A-mark processors, therefore we mounted the 1uF capacitor between V18 and V18vss due to the silicon bug in the device.

Now the unfortunate has happened, finally producing with X-mark processors but our production hasn't changed the capacitor to 10uF as we instructed.

So my question is, what's the excact influence does this capacitor have on the RTC. Its working but can we assume that it will countinue to work ?

The V18bkp voltage is 1.63VDC in standby mode.

Asking because logic_io-TJ is not in the company anymore and now i need to follow up on this. Hope you can help answer this.

Best Regards

Bomholt