Selecting a microcontroller

Ask a beginner in embedded systems, he might probably have worked on microcontroller for sure if not an any other. Microcontroller is like a heart for any low end embedded system. Yes, high end systems are for sure dominated by microprocessor or FPGA whether it be because of high performance of microprocessor/FPGA or any other factors. 

So, while choosing a microcontroller, it is always important to know the selection criteria. From the project point of view, we do get the requirements based on which selection is done. Microcontrollers are available from various vendors and selecting the best one among them is the toughest decision for a designer.Here are the list of factors based on which we will be selecting a microcontroller.

• Flash memory size
• RAM size
• GPIO availability
• Package of microcontroller
• Board size occupied by microcontroller/pin count
• 8/16/32-bit 
• Frequency of operation (DMIPS, DMIPS/MHz)
• Power consumption (sleep current, standby current, peripheral consumption)
• If pin compatibility among controllers from same vendor
• Pricing of microcontroller
• Development environment (IDE) availability
• Debugging tools
• Design support from microcontroller vendor
• Functions available (UART, SPI, I2C, ADC, PWM, etc)
• Availability Safety functions like Internal temperature sensor, watchdog timer, etc

While selecting a microcontroller, we make a list of microcontrollers and compare the controllers with the above features. some give ratings based on the differences and some based on visual inspection of differences tend to make a decision.