Hi atcold,
Good day. I have confirmed this internally and there's a number of rev updates since the early 2010s until now. You may refer to the summary of the chronological rev update below:
The old version
Old Volume 1: Device Interfaces and Integration
Old Volume 2: Transceivers
Old Volume 3: Hard Processor System Technical Reference Manual
Old Volume 4: Device Basics
The updated version:
As you can see below old vol 4 (Device Basics) has been divided and made into an updated document as the new Vol 1 and new Vol 2. It may seem overlapped, but as I said there were a number of rev updates activities that have been taken off since then.
Old volume 1 - > New vol 1 (Cyclone V Device Handbook: Volume 1: Device Interfaces and Integration)
Old Volume 2 - > New vol 2 (Cyclone V Device Handbook: Volume 2: Transceivers)
Old Volume 3 -> Cyclone V Hard Processor System Technical Reference Manual (Cyclone V Hard Processor System Technical Reference Manual)
Old volume 4 - > New vol 1 and New vol 2
Hope this can help you.
Regards,
Fakhrul