N76E003AT20 Microcontroller Unit

N76E003AT20 is a microcontroller unit from the N76E003 family introduced by Nuvoton. It is an 8-bit, low-power MCU based on 8051 architecture. Moreover, it has a total number of 20 pins, out of which 18 are GPIO pins, memory, and other peripherals.

N76E003AT20 is a high-speed controller with 16 MHz of a powerful oscillator, I2C protocol, an SPI port, and a self wakeup timer. The MCU also has an analog to digital converter, 8-channel PWM, and a fault brake for motor operations. This microcontroller unit finds its applications in consumer products and small projects.

N76E003AT20 Pinout Diagram

The following diagram presents the pinout of the N76E003AT20 microcontroller unit. The color-coding in this pinout diagram is used to distinguish various peripherals such as I2C, SPI, UART, PWM, etc.

N76E003AT20 Microcontroller pinout diagram

N76E003AT20 Pin Configuration

In this section, let’s discuss the pinout of the N76E003AT20 microcontroller.

NumberPin NameFunction
1PWM2/IC6/T0/AIN4/P0.5PWM output 2/Input Capture 6/External count input to Timer 0/ADC Input 4/Port0 bit 5 pin
2TXD/AIN3/P0.6Serial data transmission/ADC Input 3/Port 0 bit 6 pin
3RXD/AIN2/P0.7Serial data reception/ADC Input 2/Port 0 bit 7 pin
4RST/P2.0Reset/Port 2 bit 0 pin
5INT0/OSCIN/AIN1/P3.0Interrupt 0/Oscillator Input/ADC Input 1/Port 3 bit 0 pin
6INT1/AIN0/P1.7Interrupt 1/ADC Input 0/Port 1 bit 7 pin  
7GNDGround pin
8[SDA]/TXD_1/ICPDA/OCDDA/P1.6Serial data transmission 1/ICP or OCD In/Out/Port 1 bit 6 pin
9VDDPower Supply pin
10PWM5/IC7/SS/P1.5PWM output 5/Input Capture 7/SPI Select input/Port 1 bit 5 pin
11P1.4/SDA/FB/PWM1Port 1 bit 4/I2C data line/Fault Break input/PWM output 1 pin
12P1.3/SCL/[STADC]Port 1 bit 3/I2C Clock line/ADC Start trigger pin
13P1.2/PWM0/IC0Port 1 bit 2/PWM output 0/Input Capture 0 pin
14P1.1/PWM1/IC1/AIN7/CLOPort 1 bit 1/PWM output 1/Input Capture 1/ADC Input 7/Clock Output pin
15P1.0/PWM2/IC2/SPCLKPort 1 bit 0/PWM output 2/Input Capture 2/SPI Clock pin
16P0.0/PWM3/IC3/MOSI/T1Port 0 bit 0/PWM output 3/Input Capture 3/SPI in/out/External count input to Timer 1 pin
17P0.1/PWM4/IC4/MISOPort 0 bit 1/PWM output 4/Input Capture 4/SPI in/out pin
18P0.2/ICPCK/OCDCK/RXD_1/ [SCL]Port 0 bit 2/ICP or OCD Clock input/Serial data reception1/I2C Clock pin
19P0.3/PWM5/IC5/AIN6Port 0 bit 3/PWM output 5/Input Capture 5/ADC Input 6 pin
20P0.4/AIN5/STADC/PWM3/IC3Port 0 bit 4/ADC Input 5/ADC Start trigger pin
  • PWM Channels: Pulse width Modulation channels are used to produce analog signals
  • ICP: Input capture pin is used for pulse measurement of timers
  • Serial Communication ports: MOSI, MOSI, UART ports, an Inter-Integrated Circuit (I2C) interface, which included Serial Data line(SDA) and Serial Clock line(SCL), are used for serial data transmission
  • FB: A fault brake circuit to provide motor control to the controller

N76E003AT20 Features and Specifications

Features and PeripheralsAvailability
Pin Count20
SRAM256 Bytes
Watchdog TimerYes
Program Memory18 KiloBytes
Low-speed Internal Oscillator10 kHz
Internal Oscillator16 MHz
ADC Resolution12 bit
Window watchdog timer (WWDT)No
PWM channels5
PWM Resolution16 bit
Number of Timers(16-bit)2
12C module1
UART module2
Interrupt pins2
Operating Voltage2.4 – 5.5 Volts
Operational Temperature-40 – 1050C
  • DataBus Width : 8bits
  • Pin Count: 20 (TSSOP)
  • Program Memory: 18 KB
  • StaticRAM: 256 bytes
  • I2C Data Rate: 400 kbps
  • Max SPI Data Rate: 8Mbps

N76E003AT20 Peripheral Features

Some of the peripheral features are detailed below:

  • CMOS based high-speed microcontroller with Flash memory
  • It comes with two power-down modes, i.e., Idle mode and power-down mode
  • It has a code lock for the security purposes
  • An in-built wake-up timer to work in power saving modes
  • A Brownout Detection Circuit to monitor and solve power problems
  • It has two interrupts and timers
  • Integrated IAP(In-Application Programming) to update the memory through application
  • Integrated ISP(In-System Programming) and ICP(In-Circuit Programming) to reprogram the memory while installed in the system
  • A user-programmable watchdog timer with 10 kHz RC Oscillator
  • An auto-reload timer3 to serve baud rates for UARTs

N76E003AT20 Block Diagram

The block diagram of the microcontroller unit showing the processor and memory is shown below:

N76E003AT20 Microcontroller block diagram

How to Program N76E003AT20 Microcontroller Unit

To program the Nuvoton N76E003AT20 microcontroller, we need an integrated development environment and a compiler. Different software and compilers available in the market can be used to program these 8051 base microcontrollers. But Keil vision is the most widely used IDE that comes with a C51 compiler to program 8051 based microcontrollers.

N76E00AT20 can be programmed through:

  • IDE: Keil u-vision
  • Compiler: C51

Download the Keil u-vision free version from the official page and install it on the computer. You can check these getting started guide on Keil uvision:

How to Interface the Microcontroller unit?

The interfacing of the Nuvoton MCU is easy. Following are the steps:

  • Connect the microcontroller unit
  • Connect the peripherals
  • Select the serial communication port 
  • Upload the program
  • Observe the results

The following figure shows the schematic diagram of a development board based on the N76E003AT20 microcontroller.

N76E003AT20 based development board

Alternate Options

  • AT89C2051
  • AT89LP2052
  • N76E003AS20

N76E003AT20 Applications

  • Sensor Systems
  • Audio Controllers
  • Home automation systems
  • Low-cost embedded systems
  • Data Access Control

2D Diagram

The N76E003AT20 Microcontroller Unit comes in the TSSOP-20 package. The following figure shows dimensions of N76E003AT20 Microcontroller Unit.  The physical dimensions are used when a PCB card is designed.

N76E003AT20 2D Dimensions

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