Strange behaviour on uPSD SRAM.

econfalonieri · ‎2003-09-28

Posted on September 29, 2003 at 04:38

econfalonieri · ‎2011-05-17

Posted on May 17, 2011 at 11:55

FAE from Italy here. One of our customers is encountering several problems using uPSD3234 on DK3200 eval board. In particular problems are coming from internal SRAM. Customer is disabling PC2 pin as described in Errata sheet 0303 (21.03.2003) but continuosly he is having corrupted values in the register here contained. The customer is also noticing that the memory seems to remains back-up-ed by the power supply also if this functionality has been disabled by PSD Soft Express (PC2 was configured as GPIO with pin enable and pin enable was to GND). Customer asked to KEIL Electronics about this strange behaviour and KEIL verified the correct sut up of customer projects (in particular for what is concerning the monitor debugger Mon51, that initially seemed to be responsible for this data corruption). Have you some suggestion about these problems? It seems that the VSTBY function is enabled also if this is not configured by the customer.

danielh1 · ‎2011-05-17

Posted on May 17, 2011 at 11:55

I got the same problem a few months ago: this is due to a mistake on the DK3200 board. There is a PDF errata at (pretty well hiden):

http://www.st.com/stonline/prodpres/memory/psd/pdf/dk3200er.pdf

The simplest fix is to solder a 20K resistor in parallel on R34: this will rise VCC by 0.3V approximately and the low voltage detector will not inhibit anymore access to the SRAM.

I got this solution thanks to Mr Phyllis Lam at the ST technical support department. Mr Moderator, don'you think that this errata sheet should be clearly published at this forum and at the DK3200 presentation site?

Asterix