problem with st92f120

peppecaselli · ‎2005-08-29

Posted on August 30, 2005 at 04:54

peppecaselli · ‎2011-05-17

Posted on May 17, 2011 at 11:37

I have a problem with two identical circuits that use micro st92f120. The systems work with an external quartz to 4 MHz and INTCLK 20MHz. The first one works correctly. The other system goes reset every three second ones. What can be? I have changed also micro of according to system and the quartz. I do not use wachtdog hw/sw and interrupt. Help me!!!

sergio2 · ‎2011-05-17

Posted on May 17, 2011 at 11:37

you should Connect the HW0SW1 pin to Vdd through a 1K pullup

peppecaselli · ‎2011-05-17

Posted on May 17, 2011 at 11:37

Thanks Sergio!!! You have reason because it is the only one pin that it had the various voltage in the two circuits. Now they work. But the pins that I do not use, as an example AD\ DS\ RW where I must connect them? I have not connected these pins. I must connect them to Vdd or not?

sergio2 · ‎2011-05-17

Posted on May 17, 2011 at 11:37

It is always a good practice not leave floating pins

It is convenient to connect, the unused pins to Vdd or Vss,

This will also improve,l the total power consumption of the chip

peppecaselli · ‎2011-05-17

Posted on May 17, 2011 at 11:37

Thanks for your answers and the aid.

Peppe