No. Your thesis is its own piece of academic work, and one should be able to read it stand-alone. This means that you should take the relevant information, and present it to the reader, not just refer to the specifications, and give a citation.
When you need to refer to any other work, be it articles, textbooks, technical specifications or http-pages, you should follow a standard citation scheme applicable for your field. Your supervisor can help you with the relevant details regarding its setup. Note also that the example you give is actually a piece of published literature, that just happens to be available online. Also: When including http pages as references, one usually notes the date when it was accessed. This is, however, not needed in this case, as you are citing a static publication with ISBN number and everything.
In the example you give, you should write something like (modulo field dependent citation standards - also I am not a computer scientist :)):
From the UART Core specification (ref.  p. 68-69) we know that the memory mapped registers...
 ALTERA Corp (2011) Embedded Peripherals IP User Guide , Altera, e-print: https://www.altera.com/content/dam/altera-www/global/en_US/pdfs/literature/ug/ug_embedded_ip.pdf