OK, well, clever, but these days it's easier to buy the right tool for the job or use some thing like a simple FPGA demo board. Even the simplest Xilinx Sparta

OK, well, clever, but these days it's easier to buy the right tool for the job or use some thing like a simple FPGA demo board. Even the simplest Xilinx Spartan on a cheap eval board can be programmed quickly to decode just about anything and provide you with real time live data for debugging something like a serial interface. The approach he presents is laborious and far from real time.