Oct 2011
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They are popular with both professional developers and hobbyists alike due to their low cost, wide availability and large user base. The PIC has an overall of 40 pins. These pins include input/output ports such as PORTA, PORTB, PORTC, PORTD, PORTE and two Vdd ports for input voltage. The PIC architecture is characterized by its multiple attributes:Separate code and data spaces Harvard architecture. A small number of fixed length instructions. Most instructions are single cycle execution, with one delay cycle on branches and skips. All RAM locations function as registers as both source and destination of math and other functions. A hardware stack for storing return addresses. Data space mapped CPU, port, and peripheral registers. The program counter is also mapped into the data space and writable. There is no distinction between memory space and register space because the RAM serves the job of both memory and registers, and it is usually just referred to as the register file.