st7flite05 reset problem?

huaer2000 · ‎2005-05-05

Posted on May 06, 2005 at 05:44

huaer2000 · ‎2005-05-03

Posted on May 04, 2005 at 05:44

I use my own program in the evaluation board (inculded in the softec indart for st7lite09(LPT)) and found a very interesting

problem. When power up, sometimes the system works normal( some led is on), but sometimes the system works abnormal(led is off), when works abnormal, I push the reset key(I can see the negative pulse on the reset pin with oscilliscope), the system is still in abnormal, the led is still off), could anyone help me expain it. Is it because the system reset has some problem?

mcu interest

ldefend2 · ‎2005-05-05

Posted on May 06, 2005 at 05:44

The problem could be caused by the Watchdog. You know that ST7FLITE0 device has Option Bytes to set some of the device features. If you use DataBlaze you can issue an Erase command then goto the Option Bytes Window and set the Watchdog to Software, the Protections to Disable (Off), choose the right clock source (what you have set on the board) and disable the PLL.