Blurring Lines Between 8- and 32-bit Microcontrollers?

… or is the 16-bit microcontroller family dead?

Over the years, the lines have blurred between the 8-, 16-, and 32-bit microcontroller families with designers confused to when they should select which line. In Robert Cravotta’s recent article entitled “Recognizing Technology’s Inflections” he says that

“… Freescale’s Flexis and Atmel’s AVR lines blur the line between 8- and 32-bits by sharing common IP (intellectual property) between the processor groups.”

Although this is very true, and I agree completely with Robert’s statement, I wanted to make clear that there are several clear distinctions to when a designer will select an 8-bit vs. a 32-bit. But the blur is when one thinks of the 16-bit microcontroller family – a technology that is slowly ‘dying on the vine’ since the 8- and 32-bits are moving into the 16-bit space.

Let’s start with the 8-bit microcontroller family. Many engineers use 8-bit microcontrollers for applications that have typically required 16-bit microcontroller performance. These applications require a microcontroller that has scalable system performance with reduced cost, smaller size, more flash memory and lower power. A practical application may be a soda vending machine (since we all drink soda). A soda machine, let’s call it a Coke machine, may need an 8-bit microcontroller, but with a large program requirement, and still require ultra-low power performance. The Coke machine’s task is to add up the total number of sodas dispensed on a daily basis and send the data to headquarters so the delivery person can restock the sodas accordingly. Many companies today deliver microcontrollers that may fulfill these historical 16-bit application requirements of – standby, sleep for lower power consumption and smaller footprint – but with an 8-bit microcontroller. This is a typical example of how the 16-bit market is being serviced by the high-performance 8-bit market.

There is typically no doubt in a designer’s mind when he needs a 32-bit microcontroller for his application. For instance, applications in the automotive, industrial, biometric, audio, communication and web server space have intensive data computing and typically require 32-bit microcontroller performance. These applications require extremely robust computing performance yet low power consumption is always a concern. In the past, designers may select a 16-bit microcontroller to suit these requirements but with the integrated functionality of a complex-deep sleep mode in the latest 32-bit microcontroller families, they are now able to select a 32-bit microcontroller rather than a 16-bit and use the additional performance of the 32-bit while still reaping the low-power performance and smaller footprint. In addition, the 32-bit microcontrollers also include more memory and interfaces such as high-speed USB for the system designer.

Although there is a blur between 8- and 32-bit microcontrollers due to the shared IP, I believe both families are moving into the 16-bit space. In short, I believe the 16-bit microcontroller is a shrinking market with the 8- and 32-bit encroaching in its market space.

Pete Jones, General Manager and Managing Director, Microcontroller Business Unit, Atmel

I encourage you to read all of the posts for the robust design series; maybe they will inspire you to share your observations. I would love to be able to consolidate different perspectives and lessons learned with regards to robust design practices here. I suspect there are some valuable lessons to be gleaned from comparing such stories.

To make following this series easier (especially as multiple series overlap each other), I am including the index below to previous posts, both for this and the guest post channels.

Guest posts:

2010, February 15: Wireless Everywhere and Programmable Designs

2010, February 8 : Wireless baseband inflection point – SDR as a technological breakthrough

2010, February 1 : Of Windows, Newton’s, iPad’s and 10GBASE-T

2010, January 28 : Technology inflections : digital signal processing

Posts made here

2010, February 15: Inflection Points : Wireless and Programmability

2010, February 8 : Inflection Points : Wireless and SDR

2010, February 1 : Inflection Points : timeline (networking)

2010, January 28 : Inflection Points : timeline

2010, January 26 : Inflection Points