Hi all,

I'm trying to read some switches which are connected to a PCF8574 I/O expander. I use the INT output. It's connected to INT0 on a 89C668
Everything works fine only my interrupt routine is triggered more then once right after a keypress.
Reading the datasheet of the PCF I found out that the interrupt on this IC is reset when reading the I/O expander. Nothing bad there except when dthe key is still pressed after the int reset. Another interrupt is generated. What can be done to prevent the 89C668 from receiving multiple interrupts when a key is pressed?

I couldn't find anything on this site or on the net regarding this problem. Am I the only one who experiences this?

Thanks in advance

Peter Huijssen