PIC16F84A Microcontroller IC

The PIC16F84A based on the mid-range family of the PICmicro® microcontroller devices. The program memory contains 1K words, which translates to 1024 instructions, since each 14-bit program memory word is the same width as each device instruction. The data memory (RAM) contains 68 bytes. Data EEPROM is 64 bytes.

PIC16F84A designed as  an 18 pin IC also known as the beginners’ microcontroller designed based on high-performance RISC CPU. This microcontroller based on the Microchip technology presented in 1998 as a successor to the specific first sequentially programmable PIC, the PIC16C84. This microcontroller known as starting pickup for learning PIC microcontrollers programming as it contains 35 assembly language instructions as well as available at an affordable price. All instructions are single cycle (200 µs) except for program branches, which take two cycles with size of instruction of 8 bit. This PIC microcontroller operates at a Maximum operating frequency of 20MHz. Inorder to save power it cn also be operated in lower frequency.

The PIC16F84A is an 8-bit device which implies the majority of its registers are 8 bits wide. It comes with 1024 words of program memory. Meanwhile, it offers a Single pin current sourcing and sinking limit of 25mA. PIC16F84A   comes with a built-in Watchdog timer. There exist an internal timer located under the chip that can be enable or disable by programming. The timer is mainly used to rest the microcontroller when the program goes wrong or it may enter to the infinite loop.There are also 13 I/O pins that are user-configured on a pin-to-pin basis. Some pins are also multiplexed with other device functions.

These functions include:

• External interrupt
• Change on PORTB interrupt
• Timer0 clock input