CPiLD is a CPLD board for Raspberry Pi, it also has an I2C buffer chip.
I would say the major points are:
- 5 volt tolerance
- breakout to breadboard
- I/O expansion
- Interface conversion (e.g. SPI to I2S)
- education: learn HDL or logic circuits
The board is based on XC9572XL in a 64 LQFP package.
Check the docs section for a port of the XSVF player for Raspberry-Pi and more detail on the board.
The default image for the CPLD is a SPI bus expander buffer. It buffers all the I/Os and adds 8 inputs and 16 outputs.
If you think you would want one, leave a comment. If there is enough interest there will be a kickstarter for them.