The XCPLA is a replacement for the PLA in older versions of the Commodore 64. It is my rendition of the DodgyPLA by desater (see below). While the original version is made for self-etching, the XCPLA layout is optimized for professional board manufacturers.
There are two different versions of the compiled firmware provided in the build/
directory, both as JED and SVF files. The first one is called xcpla-dodgy
and contains the exact same core as the originial DodgyPLA project. The other one is called xcpla-neat
and it uses the modified core from the neatPLA project. This core implements different output delays that seem to fix issues some pepole have been experiencing on certain mainboards. Both versions can be programmed onto the XCPLA.
More information can be found in my blog post.
In hindsight, it would have been better to create a new repository for the XCPLA. But somehow I failed to do so in time, so here we are.
There is no warranty whatsoever. USE AT YOUR OWN RISK!.
Based on the work by skoe:
https://bitbucket.org/skoe/pla http://skoe.de/docs/c64-dissected/pla/c64_pla_dissected_a4ds.pdf
This design uses the Xilinx XC9536XL, which has 5V tolerant inputs essential for operation with the Commodore 64.
As opposed to skoe's design, the required CASRAM delay is implemented in Verilog instead of using additional components.
This project includes:
- A Xilinx ISE project written in Verilog for Xilinx XC9536XL
- A KiCad project including a board designed for home etching