If you go to an interview and are asked about what you did at your previous job for example, i dont want to tell them that i just wrote data into the buffer register and read the buffer once the TX_FLAG was set.
Yes! I totally agree. The misunderstanding was, I thought you were asking a question with reference to a problem you were having getting the SPI bus to work, rather than a question just to satisfy your personal interest (which is what I meant by academic).
I find it hard to believe that you would have trouble finding a job in the Electronics trade - you're clearly very good at what you're doing! Your threads on here are the best on the site in my opinion. Very good stuff.