Do programing methods cause the crystal resonator malfunction?

Posted on February 02, 2004 at 11:23

I programed 30pcs ST7FLITE29 with ST STICK recently. But there are 4pcs lite29 failed in the application board. If I change the option bytes

''osc RC oscillator OFF'' to ''osc RC oscillator ON'' and reprogram the microcontroller, it will work normally. It looks like that the crystal resonator is malfunction.

How could I to settle problem?

Thanks!

Posted on February 03, 2004 at 10:33

What do you mean failed?

If you mean error during programming,

a) are you using ICP enable/disable mode?

b) if ICP byte enable mode, then what clock?

What frequency range resonator are you using and are you sure the resonator is providing a clock in that frequency range?

Posted on February 04, 2004 at 02:53

The application does not work.

I am using ICP disable mode.

The frequency is 8MHz, and I am sure that the resonator can provide the frequency.

Thanks a lot for your warm helping.

Posted on February 10, 2004 at 06:46

I do not think the reason why the devices fail on the application board is because of the cystal resonator. It could be possible that the device is not able to come out of Reset, this will happen only if your LVD is on.

To prevent this please take the following action

- Do not connect a pull-up resistor and capacitor on the /Reset pin.

- Connect a 10nF pull down capacitor from /Reset pin to ground.

If in this case you are not able to program your device reduce the capacitor value.