Electronics For You

Home Resources Components

- Resources
- Components
- Learning Corner

# Microcontroller vs Microprocessor

May 28, 2016
57133
1
Facebook
Twitter
Google+
Pinterest
WhatsApp

Selecting the right device on which to base your new design can be daunting. The need to make the right balance of price, performance and power consumption has many implications. First, there will be the immediate technology considerations for the design you are able to embark on. However if microcontroller (MCU) or microprocessor (MPU), becomes the basis of a platform approach, the decision can have long-lasting consequences. Difference between microprocessor and microcontroller becomes an important debate at this point.

###

###

### Microcontroller vs Microprocessor: Primary Differences

Typically an MCU uses on-chip embedded Flash memory in which to store and execute its program. Storing the program this way means the MCU having a shorter start-up period and executing code quickly. The only practical limitation to using embedded memory is that the total available memory space is finite. Most Flash MCU devices available on the market have a maximum of 2 Mbytes of Program memory. This may prove to be a limiting factor, depending on the application.

MPUs do not have memory constraints in the same way. They use external memory to provide program and data storage. The program is typically stored in non-volatile memory, such as NAND or serial Flash. At start-up, this is loaded into an external DRAM and execution commences. This means the MPU will not be up and running as quickly as an MCU but the amount of DRAM and NVM you can connect to the processor is in the range of hundreds of Mbytes and even Gbytes for NAND.

Another difference is power. By embedding its own power supply, an MCU needs just one single voltage power rail. By comparison, an MPU requires several difference voltage rails for core, DDR etc. The developer needs to cater for this with additional power ICs / converters on- board.

## Difference Between Microprocessor and Microcontroller: Application Perspective

From the application perspective, some aspects of the design specification might drive device selection in particular ways. For example, is the number of peripheral interface channels required more than can be catered for by an MCU? Or, does the marketing specification stipulate a user interface capability that will not be possible with an MCU because it does not contain enough memory on-chip or has the required performance?

When embarking on the first design and knowing that, it is highly likely there will be many product variations. In that case, it is very possible a platform-based design approach will be preferred. This would stipulate more “headroom” in terms of processing power and interface capabilities in order to accommodate future feature upgrades.

#### RELATED ARTICLES MORE FROM AUTHOR

Technology Focus

### Solar Powered India

Software Reviews

### MPLAB Harmony 2.0: From in-House to Open Source

Technology Focus

### Growing Horizons of Electronic Monitoring

#### 1 COMMENT

1. Very useful information! There’s an error in this sentence: “Difference between microprocessor and microprocessor becomes an important debate at this point.”

   Log in to leave a comment

### LEAVE A REPLY Cancel reply

Log in to leave a comment

MORE STORIES
Technology Focus

### Solar Powered India