I sincerely thanks EDA board's users for providing excellent links, pdf , ppt for improving digital design basics. The ppt posted for timing analysis is superb.
I have studied morris mano but still it is not up to the mark.
Please provide some links/pdf/ppt/doc/books etc. which you found very useful so that others can also gain knowledge.
HDL Chip Design: A Practical Guide for Designing, Synthesizing and Simulating ASICs and FPGAs Using VHDL or Verilog by Douglas J. Smith, Alex Zamfirescu