TABLE OF CONTENTS PICs are inexpensive one-chip computers designed and manufactured by Microchip Technology, Inc. The acronym originally stood for Programmable Intelligent Computer, but Microchip's official name for these devices is now PICmicro microcontrollers. We will call them PICs. In 1977, General Instruments, Microchip's predecessor, developed the original PIC, the PIC1650. The PIC1650 can be though of as the grandfather of today's PICs, and its architecture, programming approach and other features directly correspond to those found in modern PICs. Its instruction set and register arrangement mirror current PICs with only minor differences.
General Instruments sold its microcontroller business in the mid-1980s to the entity that later became Microchip. Microchip's current product line includes nearly 200 PIC models with MBasic supporting more than half. Microchip has sold more than 2 billion PICs since the mid-1980s, and in 2002 was number one worldwide in 8-bit microcontroller sales, based on number of units shipped.
PICs are microprocessors, akin to the ones inside personal computers, but significantly simpler, smaller and cheaper, optimized to deal with the real world operating relays, turning lamps off and on, measuring sensors and responding to changed readings with specific actions instead of running word processing or spread sheet programs. To emphasize the outside world connection, the term "microcontroller" was coined to distinguish it from a "microprocessors." GI envisioned its PIC1650 as a means to replace dozens of discrete logic chips in computers using its CP1600 microprocessor, but immediately recognized the power of its flexible, programmable design serving as a stand-alone...
