ST7lite09 watchdog and eeprom

olivier23 · ‎2004-06-21

Posted on June 22, 2004 at 07:41

olivier23 · ‎2004-06-14

Posted on June 15, 2004 at 07:55

I have a problem with the watchdog and the eeprom.

the time max before a reset by watchdog is 2ms @ 8MHz with a ST7lite09. The time for write in eeprom is around 10ms.

Is it possible to used the watchdog and write to the eeprom without reset ?

wolfgang2399 · ‎2004-06-21

Posted on June 22, 2004 at 07:41

Hi Olivier,

while you are waiting simply you have to reload the watchdog by setting the WDGD bit in the LTCSR register. I think you will reload the timer at several other parts of your program.

Hope, the example (programmed in Assembler and in C) can help you.

;......................ST7 Assembler.....................................

;_______store values to EÂ²PROM___________________

bset EECSR,#1 ; begin the programming cycle

l_02 btjf EECSR,#1,l_03 ; while EÂ²PROM is busy...

bset LTCSR,#0 ; ... feed the dog...

jra l_02 ; ... and wait

l_e03

/*........................ C ......................*/

while(EECSR & 0x02) LTCSR = LTCSR | 0x01; /* wait & feed the dog */

I didn't test this example for the LITE09, but I think it's o.k.

woro