Digital filter as physical device I'd like to find some book or books to get information about how digital filter is built depending on specifications. Like depending on price, or speed and etc. As I know it could be built by some D flip-flops and summation blocks, but there are more kind of them depending on specs, so if it's possible to get book or website about this it would be great.
Thanks in advance.
Digital Filters as dedicated pieces of hardware are quite rate these days. Most filtering just happens on general purpose CPUs such as ARM core and may be partially accelerated by specific instruction sets or co-processor (e.g. NEON). Your smart phone or your laptop do a lot of digital filtering every day.
Dedicated filter hardware is typically part of a special purpose SOC (system on a chip) that's design for a specific  application like a cable modem or ANC processor). The filter  implementations are optimized for the specific application and &quot;configurable&quot;.