LITERATURE REVIEW

JOURNAL 2

MICROCONTROLLER

The Intel 8051 microcontroller is one of the most popular general purpose microcontrollers in use today. The success of the Intel 8051 spawned a number of clones, which are collectively referred to as the MCS-51 family of microcontrollers, which includes chips from vendors such as Atmel, Philips, Infineon, and Texas Instruments.

Some of the features that have made the 8051 popular are:

• 4 KB on chip program memory.
• 128 bytes on chip data memory(RAM)
• 32 bytes devoted to register banks
• 16 bytes of bit-addressable memory
• 80 bytes of general-purpose memory
• 4 reg banks.
• 128 user defined software flags.
• 8-bit data bus
• 16-bit address bus
• 16 bit timers (usually 2, but may have more, or less).
• 3 internal and 2 external interrupts.
• Bit as well as byte addressable RAM area of 16 bytes.
• Four 8-bit ports, (short models have two 8-bit ports).
• 16-bit program counter and data pointer.
• 1 Microsecond instruction cycle with 12 MHz Crystal.

Variants of the 8051 may also have a number of special, model-specific features, such as UART, ADC, Op_Amps, etc., making it an even more powerful microcontroller.

Credit to : Reuban, S. (2014). Desing and Implementation of A Microcontroller Based Automatic Door NAd Visitor Counter.