I have a device with 4x20 generic LCD display controlled by arm STR750 processor which is working well.
According to IEC EN 61000-6-4 standart criteia B display of device should be recovered in a while after any static discharge. ESD tests are done with 4kV per second to contact and 8kV per second for 10 seconds to glass surface of LCD and my LCD fails on both. My LCD chars displays wrongly and garbled ter a static discharge -my processor works normally-.
It keeps wrong display until end-user reset the ARM processor but IEC EN 61000-6-4 standard criteria B says it should be recovered without user interaction. So I should recover that malfunction with STR750 arm processor. Simple reinit of LCD makes it work good again.
How can I understand any malfunction occurs on my LCD that makes wrongly display by ARM processor? And Is there any robust way to recover it? I can sense it by STR750 arm processor with readback just after a write to LCD register for everytime but it is not robust.
I am asking for a method or procedure that helps me to write C code to my arm processor or a hardware trick for recovery after LCD malfunction because LCD is generic and have no info about ESD so I cant make any changes on LCD.