In a computer, you’ll usually use DIMMs, which are memory sticks external to the mainframe. however, these are so much too space-inefficient for a few comes. Microcontrollers are utilized in the embedded area, wherever lower chip count suggests that lower board prices and smaller size: each thing which will be important depending on the project. These MCUs have their DRAM engineered directly on-chip, therefore there’s solely such a lot you’ll cram on there.
Besides, as you may see, there’s an enormous quantity of selection within the MCU area. which suggests that one thing: varied demand. whereas a number of these microcontrollers end up getting used for terribly computationally-intensive stuff, plenty of them simply ought to do one straightforward job: as an example, several home appliances are controlled by an MCU. If all you would like is to close up your refrigerator’s cooling system once temps drop below a definite threshold, will it really make sense to use one thing like a Cortex M3? No. In fact, you’re likely to choose for something abundant nearer to it PIC10 MCU up above.