Atmel 8051 AT89C51 AVR 40 Pin DIP Microcontroller

AT89C51 is an 8-bit microcontroller and belongs to Atmel’s 8051 family. ATMEL 89C51, has 4KB of Flash programmable and erasable read only memory (PEROM) and 128 bytes of RAM. It can be erased and program to a maximum of 1000 times.

Port Details:

In 40 pin AT89C51, there are four ports designated as P1, P2, P3 and P0. All these ports are 8-bit bi-directional ports i.e., they can be used as both input and output ports. Except P0 which needs external pull-ups, rest of the ports have internal pull-ups. When 1s are written to these port pins, they are pulled high by the internal pull-ups and can be used as inputs. These ports are also bit addressable and so their bits can also be accessed individually.

Port P0 and P2 are also used to provide low byte and high byte addresses, respectively, when connected to an external memory. Port 3 has multiplexed pins for special functions like serial communication, hardware interrupts, timer inputs and read/write operation from external memory. AT89C51 has an inbuilt UART for serial communication. It can be programmed to operate at different baud rates. Including two timers hard interrupts, it has a total of six interrupts.

Features and Specifications of 89C51:

• Compatible with MCS-51™ Products
• 4K Bytes of In-System Reprogrammable Flash Memory - Endurance: 1,000 Write/Erase Cycles
• Fully Static Operation: 0 Hz to 24 MHz
• Three-level Program Memory Lock
• 128 x 8-bit Internal RAM
• 32 Programmable I/O Lines
• Two 16-bit Timer/Counters
• Six Interrupt Sources
• Programmable Serial Channel
• Low-power Idle and Power-down Modes

Pin Description:

• 1 - P1.0: 0th pin of PORT P1
• 2 - P1.1: 1st pin of PORT P1
• 3 - P1.2: 2nd pin of PORT P1
• ...
• 40 - Vcc: Supply pin of MCU

Other ATMEL MCU’s: AT89S52, ATMega328P

Flash Memory:

4K Bytes

CPU:

8-Bit

Maximum Operating Voltage:

6.6V

Maximum Oscillator Frequency:

0 Hz to 24 MHz

Internal RAM:

128 x 8-Bit

Programmable I/O Lines:

32

Timer/Counters:

Two, 16-Bit