The 8051 Microcontroller

The 8051 Microcontroller
The device selected for the research is the 8051 microcontroller. Intel initially designed the device in 1981. The most common features of the microcontroller include the 4kb ROM storage, 128 bytes RAM storage, 2-16 bit timers, and 40 pins Dual Inline Package (DIP) among other features (WatElectronics.com, 2019). It is also made up of the four parallel 8-bit ports and an on-chip oscillator with a crystal frequency of 12 MHZ.
Selected Features
The two features selected for the discussion in the research are the memory and the oscillator (WatElectronics.com, 2019). The memory of the 8051 Microcontroller is designed to set-up the commands. The memory controls critical activities such as performing precise tasks. The storage space is necessary for the storage of different programs which can be interpreted by the 8051 Microcontroller. The memory is designed to control all the programs of the 8051 Microcontroller and it is also known as the program memory or the Read-Only Memory (ROM). Additionally, the 8051 Microcontroller consists of the memory that store data and allows operations for the short term. The storage space is used to store data momentarily and it is known as the Random Access Memory. The oscillator acts as a timer to coordinate the function of the Microcontroller. Therefore 8051 Microcontroller is made up of the on-chip oscillator which controls the activities of the Central Processing Unit (CPU). The oscillator aids in the harmonization of all the pieces of 8051 Microcontroller.

8051 Microcontroller Architecture
The architecture of the 8051 Microcontroller consists of the buses that link the support devices to the CPU. The system also consists of the 8-bit data bus as well as the 16-bit address including the bus control signals. The other devices such as the ports, serial interferences, timers, CPU, data memory, program memory are connected together through the system bus.

Figure 1: The Architecture of 8051 Microcontroller Architecture (WatElectronics.com, 2019)
The 8051 Microcontroller Architecture consists of the multiple registers that used in programming and controlling of several hardware peripherals such as the Timers, Serial Ports, and Bus Control among others (Ravi et al., 2017). The Special Function Registers (SFRs) are used in assessing the operation of 8051 Microcontroller. The SFRs acts as the control table which monitors and changes the operations of the 8051 Microcontroller. The list of the registers in the 8051 Microcontroller contains the components such as the A or ACC, B, DPL, DPH, IE, IP, Po, P1, P2, P, PCON, PSW, SCON, SDUF, SP, TMOD, TCON, TLo, THo, TL1, and TH1 (Ravi et al., 2017). The registers perform unique functions. For instance, the Accumulator or Register A is one of the critical components of 8051 Microcontroller. The register is used in performing arithmetic operations, logical operations and data transfer operations.
Addressing Modes
The addressing mode of 8051 Microcontroller constitutes of different ways of source operand in an instruction. The addressing modes include the immediate, register, direct, register indirect and indexed (Ravi et al., 2017). Immediate addressing mode is when the source operand is constant and the operand appears after the op-code. Register mode holds the data for manipulation. Direct addressing mode is whereby the data is located at a known location and is commonly in the RAM and it is given as part of the instruction. Register indirect addressing mode is used as the pointer to the data. Indirect addressing mode is used in the accessing of the data elements of the look-up table located in the ROM storage of 8051 Microcontroller. The addressing modes manage the instructions such as arithmetic, logical, data transfer, branching, and looping, and bit control.

References
Ravi, Madhuri, Madhuri, Namdeo, A., Namdeo, A., Kharadi, J., … Rang, R. (2017, December 25). 8051 Microcontroller Special Function Registers (SFRs). Retrieved from https://www.electronicshub.org/8051-microcontroller-special-function-registers/.
WatElectronics.com. (2019, September 23). 8051 Microcontroller Architecture and Block Diagram with Applications. Retrieved January 14, 2020, from https://www.watelectronics.com/8051-microcontroller-architecture/.