There are two methods used to address the same data which is to be displayed. One is a human friendly function which is designed to represent the data as it is physically seen, the other is a single interrupt friendly array of addresses which is set out in the order that the shift register’s data is loaded out to the display

‘Human Friendly’ XY Addressing

The XY word is a human friendly function which is designed to represent the coordinates of the data as it is physically seen on the display.

This is achieved by using a table of arrays indexed at the top left of the display,  please see XY coordinates word’s page for further details.

‘Interrupt Friendly’ SpiData Array

The SpiData array is a single interrupt friendly array of addresses which is set out in the order that the shift register’s data is loaded out to the display.

This makes for a relatively easy method of retrieving the next data value required in assembly and is discussed on the dedicated SpiData Array page.