AT89S52 Microcontroller

• The AT89S52comes from the popular 8051 family of Atmel Microcontrollers. It is an 8-bit CMOS microcontroller with 8K as Flash memory and 256 bytes of RAM. Since it is similar to the trust worthy 8051 architecture these microcontrollers are as per industry standard.
• It has 32 I/O pins comprising of three 16-bit timers, external interrupts, full-duplex serial port, on-chip oscillator and clock circuitry.
• The Microcontroller also has Operating mode, Idle Mode and Power down mode which makes it suitable for battery operated applications. Few considerable drawback of the microcontroller is that it does not have in-built ADC and does not support SPI or I2C protocols. However you can utilise external modules for the same.
• It is a high-performance CMOS microcontrollers with Flash Technology
• The unit operates at a wide range of 4 – 5.5 volts, so it is a low power IC.
• The device supports In-system Programming both page and byte mode for the Flash memory.
• The operational frequency of CPU is up to 33MHz but can be altered for saving energy.
• The module has a quick programming time with 10,000 read/write cycles.
• The Random Access memory is organized in 256×8 bits.
• The serial communication takes place through a full duplex UART module.
• It comes with a reset option, three 16-bit timers and eight interrupts.
• AT89S52 has two power modes, i.e., idle mode in which  stops processing unit stops while other peripheral keep working and power-down mode that halts oscillator and other functions and save RAM contents.

Pinout Configuration

• Pin 1(P1.0 (T2))Timer/Counter or 0th GPIO pin of PORT 1
• Pin 2(P1.1 (T2.EX))Timer/Counter/External Counter or 1st GPIO pin of PORT 1
• Pin 3(P1.2) 2nd GPIO pin of PORT 1
• Pin 4(P1.3)3rd GPIO pin of PORT 1
• Pin 5(P1.4)4th GPIO pin of PORT 1
• Pin 6(P1.5 (MOSI))MOSI for in System Programming or 5th GPIO pin of PORT 1
• Pin 7(P1.6 (MISO))MISO for in System Programming or 6th GPIO pin of PORT 1
• Pin 8(P1.7 (SCK)) SCK for in System Programming or 7th GPIO pin of PORT 1
• Pin 9(RST)Making this pin high will reset the Microcontroller
• Pin 10(P3.0 (RXD))RXD Serial Input or 0th GPIO pin of PORT 3
• Pin 11(P3.1 (TXD)) TXD Serial Output or 1st GPIO pin of PORT 3
• Pin 12(P3.2 (INT0’)) External Interrupt 0 or 2nd GPIO pin of PORT 3
• Pin 13(P3.3 (INT1’)) External Interrupt 1 or 3rd GPIO pin of PORT 3
• Pin 14(P3.4 (T0))Timer 0 or 4th GPIO pin of PORT 3
• Pin 15(P3.5 (T1)) Timer 1 or 5th GPIO pin of PORT 3
• Pin 16(P3.6 (WR’)) Memory Write or 6th GPIO pin of PORT 3
• Pin 17(P3.7 (RD’))Memory Read or 7th GPIO pin of PORT 3
• Pin 18(XTAL2)External Oscillator Output
• Pin 19(XTAL2)External Oscillator Input
• Pin 20(GND) Ground pin of MCU
• Pin 21(P2.0(A8)) 0th GPIO pin of PORT 2
• Pin 22(P2.1(A9))1^stGPIO pin of PORT 2
• Pin 23(P2.2(A10)) 2^ndGPIO pin of PORT 2
• Pin 24(P2.3(A11)) 3^rd GPIO pin of PORT 2
• Pin 25(P2.4(A12)) 4^th GPIO pin of PORT 2
• Pin 26(P2.5(A13)) 5^th GPIO pin of PORT 2
• Pin 27(P2.6(A14)) 6^th GPIO pin of PORT 2
• Pin 28(P2.7(A15)) 7^th GPIO pin of PORT 2
• Pin 29(PSEN’)Program store Enable used to read external program memory
• Pin 30(ALE / PROG’)Address Latch Enable / Program Pulse Input
• Pin 31(EA’ / VPP) External Access Enable / Programming enable Voltage
• Pin 32(P0.7 (AD7))Address / Data pin 7 or 7th GPIO pin of PORT 0
• Pin 33(P0.6 (AD6)) Address / Data pin 6 or 6th GPIO pin of PORT 0
• Pin 34(P0.5 (AD5)) Address / Data pin 5 or 5th GPIO pin of PORT 0
• Pin 35(P0.4 (AD4)) Address / Data pin 4 or 4th GPIO pin of PORT 0
• Pin 36(P0.3 (AD3)) Address / Data pin 3 or 3rd GPIO pin of PORT 0
• Pin 37(P0.2 (AD2)) Address / Data pin 2 or 2nd GPIO pin of PORT 0
• Pin 38(P0.1 (AD1)) Address / Data pin 1 or 1st GPIO pin of PORT 0
• Pin 39(P0.0 (AD0))Address / Data pin 0 or 0th GPIO pin of PORT 0
• Pin 40(Vcc)Positive pin of MCU (+5V)

Applications

• Multiple DIY Projects
• Very good choice if you are learning ATmel
• Projects requiring Multiple I/O interfaces and communications
• Replacement for Arduino Module
• Ideal for more advanced level A/D applications in automotive, industrial, appliances and consumer applications.