2 articles were written in July 2012:

So it’s finally time for the second part of my implementation. It took a while longer than intended, part because I changed more than originally intended.

Main goal was to connect to CPLD to a micro controller, to read out the counter results. The easiest way for the MCU would have been to provide a serial data stream (like SPI). But since we have 48 bits to transfer, I would need a 48 bit shift register - and there aren’t 48 registers left in the XC9572XL. So I did go an easier route and just build up a large multiplexer.