Introduction MCS-51 Microcontroller Family
The ATMEL 89C51 microcontroller is the most popular microcontroller of all times, it was developed by ATMEL and later it allowed other manufacturer to develop same hardware with their own name. So for this purpose all details including datasheets and other important details were shared to other major component manufacturer for further production. You can download datasheet AT89C51 microcontroller here. Basically it is low power CMOS 8 bit microcontroller with high performance MCU. It holds 4K Flash memory which is programmable. A high density nonvolatile memory highly advanced technology is used to manufacture devices and industry standard MCS-51 instruction set and pin diagram.
Datasheet 8051 Microcontroller Family Variants
AT89C1051, AT89C2051, AT89C4051, AT89C51, AT89C52, AT89C53, AT89C55, AT89S51, AT89S52, AT89S53, AT89S8252
Features ATMEL MCS-51 Series Microcontroller Family
- MCS-51 architecture which is compatible for other family members.
- Available in 1K, 2K, 4K bytes of Flash Memory for firmware storage
- ISP support, benefits of In System Reprogrammable memory as Flash
- Up to 1000 Write and Remove/Erase firmware cycles.
- 0 Hz to 24 MHz fully static functional operations.
- Firmware locking up to three level of memory security lock
- Internal Random Access Memory 128 x 8 RAM bit Internal
- Input/output 32 bit programmable lines/pins
- Two 16 bit Timers for timing operations
- Two 16 bit Counters to count external events.
- Six Interrupt handling routines to handle interruption mechanism
- Serial Communication pin using RS232 Protocol
- Low power mode for power saving
- Power down mode and idle mode saves hardware resources.
It supports In System Programming or a conventional programmer to download firmware into nonvolatile memory of 80C51 based microcontroller and later ISP was integrated in every devices so it become 89S series. You can read full details when you download datasheet AT89C52. A combination of 8 bit central processing unit CPU with on chip Flash memory ATMEL revolutionized the technology and offered power full MCU based highly cost effective solution and flexible application. Download AT89C52 datasheet and it brings you full details about microcontroller and its features are as follows. It is equipped with 4 K bytes of programmable Flash memory and 128 bytes of internal Random Access Memory, input output ports includes 32 pins with various important functions. Two 16 bit times and counters are integrated in the device for timing operations and counters are used to measure external events to capture. It also offers serial communication using RS232 protocol, a standard used for serial communication with microcontroller. A full duplex serial operation can be performed by the microcontroller. In built on chip oscillator for clock frequency. As an additional features AT89C52 is designed basically for two operations frequency for embedded applications development. It supports power saving modes which makes it very cost effective and less power consuming. The Idle mode features which plays important role in energy saving and cost effectiveness. In Idle mode CPU stops working but other operations of the microcontrollers like RAM, serial communication using RS232 protocol, working of timers and counters, functioning of interrupt handling works perfectly in idle mode also. Another key feature of AT89C52 is the power down mode which saves the random access memory RAM content as intact but it stops the oscillator and internal clocking mechanism, disabling oscillating clock until next reset through hardware intervention.
VCC Pin : Every electronic circuit needs positive voltage for functioning here also AT89S52 and other family members needs positive 5 volts.
GND Pin : Ground pin is used to supply negative end of the power supply, these two pins are most important, without which a system will not run.
Input/output Ports: Each I/O 40 pin variant of Atmel microcontroller comes with 4 ports and each port has 8 pins for input and output data. These are Port 0, Port 1, Port 2, Port 3. All these ports are bi-directional to accept and transfer data to external devices. An embedded systems communicates with external world and devices using these ports.
Port Pin Alternate Functions:
P3.0 RXD : Serial Port Receive Pin used to get data serially.
P3.1 TXD :Serial output port used to transmit bits serially.
P3.2 INT0 : External interrupt 0
P3.3 INT1 : External interrupt 1
P3.4 T0 : Timer 0
P3.5 T1: Timer 1
P3.6 WR : external strobe for write data.
P3.7 RD : External Strobe to read data.
RST Pin : This pin is used to reset the hardware and restarts the application.
ALE/PROG : ALE is used as latch for using external memory, and the same pin is used to Flash programming.
PSEN : Stands for Program Source Enable is used as strobe to read external memory.
EA/VPP : External Access Enable and EA must be bound with GND pin as mandatory to work with this pin. It is used to read the code from external locations of memory starting from 0000H up to HHHH.
Idle Mode : During idle mode all operations of the chip and peripherals remains active and running except CPU. This mode is activated by software instruction.
XTAL1 and XTAL2
Input pins of oscillator amplifier for internal clock operating circuit. A crystal is attached is used to generate clock pulses.
Datasheet AT89C51 Pdf
Datasheet AT89C52 Pdf
Datasheet AT89S51 Pdf
Datasheet AT89S52 Pdf