Do you ever wonder that a number of our gadgets can run for a longer time without even changing the battery? Also, some of our gadgets can run without even charging! Yeah, quite interesting, right? Yes, this is also possible. There are lots of low-power loss & low-power drawing components used in today's gadgets that help them work for a longer life. Here, Microcontrollers or MCUs are the brains of these components & they draw more current than the other components. But we have very few MCUs that can maintain this type of technical work. Yes, MSP43O MCUs do that job even if the current drawn is less than 1 microampere in ultra-low power mode! Ok, don't worry, I am here to tell you more interesting facts about this.

First of all, let's talk about MCUs. Microcontrollers or MCUs are small single-core integrated circuits or short-term microchips. It differs from your desktop or laptop computer. Those MCUs are typically dedicated to perform single tasks at a time. But if I talk about Microprocessors or MPUs, they can perform multiple tasks at a time. Also, MPUs are quite expensive than MCUs. So, you have to pay some extra money to buy an MPU.

The MSP430 MCU is based on the von-Neumann architecture & the MSP430 CPU uses a 16-bit CPU register. The MSP430 MCU Von Neumann architecture has one address space shared with special function registers, peripheral control registers, RAM, and Flash or ROM memory.

Computer Architecture that made our Technology: -

Two types of Computer Architecture make readers more confused. One is Harvard Architecture & another one is Von Neumann Architecture.

Harvard Architecture is such a type of computer architecture that contains two separate storages for instruction & data. The term Harvard Architecture is derived from the Harvard Mark I (“The IBM Automatic Sequence Controlled Calculator (ASCC), Called Mark I by Harvard University’s staff, as a general-purpose electrochemical computer.”; (Source: Wikipedia)). That stored instruction on punched tape (Punched Tape consists of a long paper strip in which holes are punched. It is generally used for storing data in the 19th & 20th centuries. But in the 21st-century use of punched tape is very rare.) & Data in electromechanical counters It contains separate storage & separate BUSs for instructions & data. The main advantage of using a separate BUS is: it takes only one cycle to complete instructions & for that reason, it also requires fewer CPU cycles. Nowadays, Von Neumann Architecture machines are used & they provide a lot better performance than Harvard Architecture.
The Von Neumann Architecture is such a type of computer architecture where instruction fetch and data operation can’t occur at the same time because they share a common BUS. The term ‘Von Neumann Architecture’ has evolved to mean any stored-program computer

(“A stored-program computer is a computer that stores program instructions in electronically or optically accessible memory.”; (Source: Wikipedia)).

The Von Neumann architecture consists of a single, shared memory for programs and data. This is also a disadvantage that only one BUS can be accessed at a time. For this result, the CPU becomes idle as it is faster than a data BUS. PIC30 & PIC32 MCUs made of Von Neumann architecture & even all kinds of ARM Processors starting from ARM Cortex-M0+ is using Von Neumann architecture. Now, a question may arise: then why are we using Harvard Architecture or any application in modern days? Yes, primarily Harvard Architecture is used for small embedded computers & signal processing. This Architecture is commonly used within CPUs to handle the cache & results from data and instruction can be obtained at the same time. Also, AVR (Ex-ATmega328/ATmega328p MCU) MCUs use Harvard Architecture. In the case of PIC Microcontrollers (Peripheral Interface Controller- used for programming a vast range of tasks), that microcontroller family is based on Harvard architecture where program and data BUSs are kept separately. The PIC18F microcontroller family is one of the popular examples where Harvard Architecture is used.

“The von Neumann architecture is based on the fact that the program data and the instruction data are stored in the same memory unit.” (Source: techcomputerscience.com)

Moreover, in the case of Harvard Architecture, the processor takes two cycles to complete an instruction whereas, Von Neumann architecture takes one clock cycle to execute an instruction. The von Neumann architecture consists of a simple Control Unit design as compared to Harvard Architecture. For that reason, Von Neumann's architecture requires fewer complex circuits and makes it less costly.

Now some people may want to know more about MCUs or may want to make some projects using MCUs. Well, now I am telling you about different kinds of MCUs which are useful and you can make your projects also.

Some Popular Microcontrollers: -

1. ATmega328/ATmega328p Microcontroller (MCU): -

ATmega328 or ATmega328p (ATmega328 & ATmega328p both microcontrollers are the same architecturally; But the main difference is ATmega328p consumes less power than ATmega328.) microcontroller is a single-chip microcontroller based on Harvard Architecture 8-bit RISC (Reduced Instruction Set Computer; RISC is such type of processor architecture that utilizes small, highly-optimized set of instructions) processor core. The Clock Frequency is Single Clock Cycle Execution. The bandwidth of the Datapath is an 8-bit low-power AVR Microcontroller. Size of Flash memory is 32k Bytes. The number of pins is 32. It has an Analog-to-Digital Converter & there are 8 bits of precision. ATmega328/ATmega328p microcontroller is used in basic Arduino boards (Ex- Arduino Nano, Arduino Uno, Arduino Pro Mini). This MCU is very popular & we can make lots of projects and autonomous systems where a very low-powered, low-cost microcontroller is needed. On the Arduino Uno, ATmega328/ATmega328p comes pre-programmed with a bootloader that allows you to upload your own new code. It is very easy for those who are new to IoT (Internet of Things) & want to make some projects (Ex- Line following Robot, Obstacle avoiding Robot, Photoresistor, Temperature Sensor etc.) & it has a wide variety of uses. You can use Arduino IDE if you want to program Arduino Uno, Arduino Nano or etc.

2. MSP430 Microcontrollers (MCUs): -

MSP430 microcontrollers (MCUs) are 16-bit low powered, von Neumann Architecture based microcontrollers. The bandwidth of the Datapath is 16 bits. The number of pins is 20. It has an Analog-to-Digital Converter & there are 10 bits of precision. The current drawn in idle mode is less than 1 microampere. The top CPU speed is 25 KHz - 35 MHz & it can be throttled back for lower power consumption. The MSP430 is also capable of wake-up times below 1 microsecond. That allows the microcontroller to stay in sleep mode for a longer period of time and minimize current consumption. But they have some limitations i.e., MSP430 doesn’t have an external memory BUS. These MSP430 MCUs are used for variety Automation projects i.e., Smart Speakers, Building Automation (Smart building product, Smarter sensing, energy & power efficiency features allow to monitor), Factory Automation, Building Security systems, Different kinds of monitoring applications (e.g.- such as medical, E-meter products), Capacitive touch, Flowmeter sensing, Smoke Detector, etc. If you want to program MSP430, you can use Code Composer Studio IDE (CCS) & Energia IDE.

3. RP2040 (MCU): -

The RP2040 based Microcontroller board does not contain any internal Flash Memory. But externally we can extend up to 64 Mb Flash Memory. This is based on Dual-Core ARM Cortex- M0+ RISC-B architecture at up to 133 Mhz. The RP2040 is available on the Raspberry Pi Pico. Raspberry Pi Pico has USB 1.1 Host & Device support. The special features of these MCUs are PIO (Programmable input/output block). It has 2 programmable IO PIO blocks and 8 state machines That supports Variety of input standards. This can be used in a variety of projects in the IoT, analog sensing, small to medium scale robotics projects, etc. You can program it using Micro Python, C/C++, Assembly, Circuit Python.

Manufacturer Companies of I. Cs I’ve mentioned: -

Conclusion:-

Now, you may think that if we omit the microcontroller family from our daily life, what's wrong? That's a crazy question! No problem, then we will go back to some decades ago and then we will start writing letters to our friends instead of emails, WhatsApp & will wait for a long time to get back our reply. ‘Microcontrollers are Everywhere’, from smartphones to the washing machine, Refrigerator to Air Conditioner everywhere we use microcontrollers. ARM Cortex-M3 microcontroller used in smartphones, washing Machine (This is very suitable for motor drive, system control (display, buzzer, voice etc)), also PIC16F877A microcontroller used for Air Conditioner. Now think back again, do you really want to use a device without having microcontrollers? It is almost impossible to live without our beloved tiny chip.