Documentation for VDHL source code of "Resurrector" ################################################### This code originates from the Prometheus upgrade project. It is a 1:1 translation from Altera legacy HDLs to modern VHDL code. The projects (PCIL and PCIH) are targeted at Xilinx CPLDs, namely the XC95144XL series. Both projects have been carefully translated and simulated, but never made it into real hardware (I have PCB layouts for such a card "on ice", so in case, I can make this public too on request). Please carefully read the license.txt file enclosed in this package. Please use Xilinx ISE 14.6 for the first step. More modern versions may work, too. In case of questions - ask me. It may take some time for me to answer, as I have always some nerdy projects going on, and last, but not least, some family business (consider this as NMI). Coding conventions ################## All port signals carry "_IN", "_OUT" or "_INOUT" at the end, to designate signal flows (except top level entities, I assume that you are familiar with Zorro III and PCI, or at least you want to get to). Top level entity signals starting with "Z_" target the Zorro III bus, "P_" the PCI bus, and "I_" signals serve as interconnection between PCIH and PCIL CPLDs. PCIH CPLD ######### This CPLD acts as Zorro III autoconfig slave, and takes care of PCI bus accesses. In addition, it features a PCI arbiter which is crucial for mixing Zorro III and PCI bus actions. Don't be confused - the real Zorro III access is handled in PCIL CPLD. PCIL CPLD ######### This CPLD takes basically care of all low level bus timings. It seems quite simple, but has a few potential pitfalls. Take care especially on how the /SLAVE latch is being constructed, the XC95144XL series doesn't have hardware latches, and while it is simply to get all kinds of unwanted latches in VHDL, it's not so straight forward to get a fully functional latch if your really need it :) And at the end... ################# Have fun. I'm happy if you can use this code to better understand Zorro III and PCI. For me, the Amiga hardware teached me the basics of my job, and I'm happy every time to see that design approaches made in the 80s still work perfectly nowadays, be it in space, or on the ocean floor. Thanks, Dave. Michael Boehmer (mboehmer@e3b.de) 2018.12