I want to off load the ultrasonic drive off of the 89C52 I have to a cpld. My problem is I'm not sure the best way to generate the 44khz drive using the cpld. Count down of main cpld clk etc. I've looked around the net, including here and Xilinx. I know this isn't really 8052 specific but cplds make nice mates for them. I just need a better vhdl book.....sugestions?