Question: Is Quad SPI really a serial interface, a parallel interface or both?
EDIT: The question here is different from mine. The question deals with the different topologes of SPI while my question is on Quad SPI in particular and to identify clearly the interface nomenclature.
It is only to gain better understanding on how we classify the serial and parallel interface in case of Quad SPI. This is a discussion which has arised many times but could not be answered well enough by me.