Last year Springer provided some books on Verilog, VHDL, digital design, etc for free. I haven’t reviewed them, but you might want to check if the can still be downloaded.
On the other hand, while I was at university, they recommended us Computer Architecture, Fifth Edition: A Quantitative Approach, Patterson & Hennessy; Computer Organization and Design, Fourth Edition: The Hardware/Software Interface, Patterson & Hennessy and Digital Design and Computer Architecture, Harris & Harris. However, I haven’t checked any of them. Additionally, the reference book for the basic digital electronics subject that I took was Digital Design and Computer Architecture (2nd Edition), David Money and Sarah Harris. Elsevier- Morgan Kauffmann, 2012