Chapter 1 - Microcomputer Systems

Abstract

Publisher Summary This chapter focuses on microcomputers that consist of a single silicon chip. Such microcomputer systems are called microcontrollers. The term “microcomputer” means a system that includes a microprocessor, program memory, data memory, and an input/output (I/O). A microcomputer system can be anything from a large computer system having hard disks, floppy disks, and printers, to single chip computer systems. The microprocessor consists of a central processing unit (CPU) and the control unit (CU). Microcontrollers have moved into the 16-bit market. 16-bit microcontrollers are high-performance processors that find applications in real-time and compute intensive fields such as, digital signal processing or real-time control. Some of the 16-bit microcontrollers include large amounts of program and data memories, multichannel analog-to-digital converters, a large number of I/O ports, several serial ports, high-speed arithmetic and logic operations, and a powerful instruction set with signal processing capabilities. The 8051 is an 8-bit, low-power, high-performance microcontroller. There are a large number of devices in the 8051 family with similar architecture and each member of the family is downward compatible with each other. The AT89C2051 is a low-end member of the 8051 family, which contains a 2 Kbyte flash programmable memory (PEROM). The AT89C2051 contains 128 bytes of RAM and 15 programmable I/O lines. The code developed for this device runs on a standard 8051 without any modification.