SPI Serial Memory Access Methods

In order to understand the structure of the provided drivers, it is necessary to review the different methods of serial memory access.

All accesses follow this sequence:

1. 1.The chip select line is driven low.
2. 2.A number of serialized bytes are sent or received synchronously to the SCK clock on the data lines.
3. 3.The chip select line is driven high.

The number and values of the serialized bytes depends on the access type.

The SPI memory devices of this application note both support SPI mode 0 (0,0) and mode 3 (1,1). In the proposed driver mode 0 is selected (see the serial memory device datasheets for details).