need books about digital clock circuit based fpga

Hi Anssam, salam

You need an altera development board and its data sheet should give good guide. Digital clock should be straighforward. You need to run a clock inside fpga, then convert it to 1 sec pulse using counter, then use three more small counters. one for seconds (0~59), one for minutes(0~59), one for hours (0 ~ 23 or 0 ~ 11).

What is left is read these counters and decode values for display.

As you work through, we can help here.

Wa domtom

thank u very very much

thats very kind of u.

if i need some thing can i asking u??

I recommend taking a look at these:

http://www.altera.com/literature/hb/qts/qts_qii51007.pdf

The templates menu in Quartus II (with a verilog file opened in Quartus)

Study existing code out there (take with a grain of salt since there are some very poor code out there)