XC9572XL CPLD protoboard

This is a small board that contains a PLCC44 socket that can accept various CPLD's like the XC9572(XL,XV) and the XC9536(XL,XV).
I made 2 of these boards, the first one contains pinheaders as connections to a breadboard, something i cant advise. Pinheaders pins are quite thick and damage the holes on breadboards, i have mostly switched to CUP pin headers, they more resemble IC pins and are more friendly to the holes in breadboards. Therefor the second has been removed from this page.

Construction

there is a PLCC44 socket at the center for the CPLD, all of the pins are connected to 18 pins at each side.
Each power pin pair is decoupled by a 10nF and a 100nF X7R ceramic capacitor. the power rails are decoupled by a 2.2uF tantalum underneath the CPLD and a 330uF aluminium electrolytic at the underside. This is mostly to decouple all the power rails correctly and sufficiently on all frequencies, a CPLD is a high performance CMOS chip and benefits from this kind of decoupling, expecially when using high speeds. There is a excellent application note about this on the xilinx website, it explains why you need different capacitances and how to lay them out. A must to read.
There is a socket on top of the board that accepts a 16 pin length clock oscillator module and is attached to globalclock 1.
The bottom has a 10 by 2 pin header for the programmer plug so you can easely program the CPLD on the board.

Here is a small project. A 16 random linear shift register making some leds blink.

Back

Last update at: 26-06-2005