I have write a program for data logging.
It uses the timer 0 interrput to generate the time and use the SPI ADC chip to get the measured data.

My problem is the, when the 89s8252 is communication with the external SPI ADC chips. At the same time, the timer 0 interrupt occur and jump to the interrupt rountine(these rountine just do not affect the I/O). It resulted some error data(data loss).

My idea is that ,during interruptrountine, all to external I/O will remain the same. After the interrupt rountine completed, the uP will return to the previous code. That's mean it should not affect the SPI commnication.

However, SPI is affected by Timer interrupt.

any comment about it?
pls help
thanks.