Hardware Design 1

Once the system is designed and the hardware requirements are established, the next step is to design the actual hardware. Embedded microprocessors fall into two broad categories: single-chip embedded solutions with on-chip memory like the 8031 and embedded systems using a microprocessor with external memory and input/output (I/O). Examples of these are a 68000-, 80186-, or 386EX-based embedded system. Single-chip microprocessors (or microcontrollers) usually provide erasable programmable read-only memory (EPROM; or ROM or flash memory), random access memory (RAM), and I/O ports. Most also have internal timers, serial interfaces, or other peripherals. The I/O ports are flexible, permitting each bit to be assigned as input or output. The actual design of single integrated circuit (IC) systems is straightforward. Before starting the design, it is important to make sure that there are sufficient I/O port pins, enough internal memory, and sufficient processor speed to do the job.