[SOLVED] what is digital/mixed-signal blocks

Hi
i want to know what is the digital/mixed signal.
i think it is both analog and digital but how i design and implement
does i write my design using HDL language .

Which HDL - there are several?

For starters see https://en.wikipedia.org/wiki/Mixed-signal_integrated_circuit

The analog portions are not designed via HDL methods, but the digital portions could be depending upon how complex and large they are, and whether the overhead of an HDL synthesis flow makes sense for it.
There are also terms "big-A/little-D" and "big-D/little-A" indicating which domain dominates the IC's die area and design content.
The design and layout of the interface and power-supplies between the A and D is also typically critical, mainly to prevent digital switching noises from interfering with analog accuracy.

There is no simple answer on how to get to the point of becoming competent at (including all the EDA tools needed for) designing a mixed-signal IC.
Do web-searches and look for University coursework presentation slides for more info (or textbooks on Amazon.com).
There are also online videos that might be helpful here: **broken link removed**

thank's alot