The first feature discussed will be the data buffer. The example shown here illustrates the tracking of a stylus on a touch screen. If the stylus moves very quickly or the CPU is busy and cannot process the data immediately, the data buffer will retain up to one hundred and twenty-eight sets of data. That is, twelve bits for X coordinates, twelve bits for Y coordinates, and eight bits for Z coordinates along with the touch pressure data. The example figures show what would be drawn on the screen with and without a data buffer.