How about a parallel port with hand shaking.   A little state machine
in the FPGA to interface to the cdata and control lines.

george

Hi,
I am currently working on Cygnal's C8051F022....I need this to
communicate with a Xilinx FPGA on the board....I am using Port 0 for
talking to the FPGA.....What i need to do is..as follows:

I have an 8 charactor display and two momentary contact switches...
One switch is for selecting menu and another is for entering tat value
The microcontroller takes care of the two switches and the LED display
I need to have a menu selection which selects two parameters A and B
and then changes the angle information..increment or decrement...
Accordinly these values should change in the FPGA..
I am also using a rotary encoder for incrementing and decrementing the
values

Any ideas or suggestions about this is welcome

Thankyou,
Methi