Hi,
Yes i was planning to use AT89c52 but as you said it does not have PCA registers.

i have changed my controller by intel Intel 87C151SA which is compatible with Intel 87C51FA devices.

But still i have the same problems
(Error A45: undefined symbol (passs-2))
i dont know what how to correct these problems, so i hope to find some one to guide me to solve these things.

also the main problem is that i have designed my board with AT89c52, but now i have changed only the controller, so could any one tell me is it possbile to remove AT89c52 from my board and replace it with Intel 87C51FA, is it possible to do that.
i mean is the Pins configuration is the same or not.

thanks
Albarkani