Hi, I use AT89S52 in a project. I send and receive data through TXD, RXD pins to a GSM module for sending SMS to another mobile equipment. I use watchdog facility and the watchdog counter is reset at every 256 counts. My crystal frequency is 11.0592 MHz. It happens once in a while that the uC doesn't respond and remains as if it hangs. Then it has to be RESET again. I doubt whether it happens while serial data reception and sending happens simultaneously. I wrote the program in C using KEIL IDE. My questions are 1) What are the special precautions to be taken in this case?(sending and receiving simultaneously) 2)why this happens even when the watchdog is active? It will be highly appreciated if anybody can give some guidance.
assuming your watchdog is working and configured to reset the MCU, it is safe to assume that your program ends up in a condition in which it services the watchdog but not performing its main function.
I thought of that possibility. But still unable to find out any reason.
Which possibility?
program ends up in a condition in which it services the watchdog but not performing its main function.
And why you really, really shouldn't be using one in an application like this:
www.8052.com/.../119931
THANK YOU VERY MUCH. Really useful information.
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