Programming Embedded Systems, 2nd Edition

Hardware Basics

The next step in understanding the hardware is to take a look at the schematic. A schematic is a drawing comprised of standardized symbols to represent all of a circuit’s components and connections. The schematic gives the details of the hardware, showing the individual components represented in the block diagram, how the components are interconnected, and, most importantly, where to put the oscilloscope probe to see what’s going on with a particular circuit. On most projects, it is not necessary for you to understand how every electrical circuit on the board operates, but you do need to understand the basic operation of the hardware.

Along with the user’s guides or manuals for the board, it is also helpful to collect the datasheets for all major components on your board. The datasheet is a complete specification of a particular hardware component, including electrical, timing, and interface parameters.

Often the hardware engineer has already collected the datasheets; if so, your work is partly complete. You might want to take a look at the other information available for a particular component, because there are often separate hardware and software documents, especially for more complex devices. For example, a processor often includes a Programmer’s Guide in addition to the other literature. These documents can give you valuable information for using various features of the processor; they occasionally even provide code snippets.

There are also application notes ...