Chapter 9. Memory I/O Interfacing
IN THIS CHAPTER
Skiers and snowboarders want snow and short lift lines. Silverjack supplements natural snowfall by using snow-making equipment. The Project Trailblazer engineers want to provide guests with lift status information. In Chapter 7, "Parallel Port Interfacing,"the engineers interfaced lift monitoring and snow-making equipment to the x86 parallel printer port, using an interface circuit connected to six input and four output modules. The ARM and PowerPC target boards also have the capability to monitor the lifts and control the snow-making equipment. The MediaEngine and the RPX-CLLF don't have parallel printer ports, but they do offer expansion connectors that are perfect for memory-mapped input/output (I/O).
This chapter discusses how the Project Trailblazer engineers redesigned the lift monitoring and snow-making control interface circuit and device driver software module. This chapter steps through the process of designing memory-mapped I/O hardware, configuring the CPU registers, and developing the driver software for the ARM and PowerPC target boards.