background
Under Your Radar
Microcontrollers You Should Know About
By Clemens Valens (Elektor)
The global micrcontroller market is more diverse than many people think. Let’s take a look at some of the microcontrollers and manufacturers that are not often seen in Elektor. You might find one or more of them useful in a future project. The choice of microcontroller for an Elektor design is mostly based on the availability of low-cost software development tools and device programmers and the possibility for individuals to buy it. As a result, many electronics enthusiasts have a rather limited view of the microcontroller market worldwide. There is much more out there than the PIC, AVR, ARM or ESP devices we encounter so often in DIY projects. Let’s have a look at some of the MCUs that live in your blind spot.
It All Started With Four Bits
Introduced in 1971, the Intel 4004 is said to be the first commercially produced microprocessor (more about it can be found in our Elektor Industry Special about 60 years of electronics [1]). It was a 4-bit device. Together with its support chips it formed the MCS-4 family. It was followed up by the MCS-40 family with 4040 CPU. Texas Instruments’s first successful microcontroller (not a microprocessor), the TMS1000 from 1974, also was a 4-bit device that, like the 4040, found its way into many pocket calculators.
In a world where microcontroller manufacturers seem to strive for data words as wide as possible, 64 bit is not uncommon, you would be surprised by the number of 4-bit microcontrollers that are still being used today. But why? The answer is probably a mix of legacy, power consumption and cost reasons. A 4-bit MCU can be built with fewer transistors than devices with a wider word width. Therefore, all other things equal, they consume less power which helps increasing battery life. Fewer transistors also means less space and so a 4-bit core can be crammed on a corner of a chip when space for a larger core is lacking. As a die it can be smaller too, saving costs (even though one might wonder how much). High-volume applications like calculators, timers, clocks and watches, bicycle computers, toys and remote controls make use of 4-bit MCUs and have done so for many years. As manufacturers usually avoid modifying products that have proven
themselves in the field – if it ain’t broke, don’t fix it – this explains why there still is a market for such devices. In case you would like to try out a 4-bit microcontroller, have a look at the NY... families from Taiwan-based Nyquest. Development tools can be downloaded for free (Figure 1). Other manufacturer examples are EM Microelectronic from Switzerland, CR Micro from China and Tenx Technology from Taiwan.
8051
Before ARM became the main MCU core provider for almost every semiconductor manufacturer on the planet, there was the 8-bit 8051. Created by Intel in 1980 as MCS-51, the core (Figure 2) was licensed to several competitors, and it found its way into a plethora of products. Many of these products or their derivatives, variants, and siblings are still being produced today, and, 40 years after its introduction, 8051-derivatives are actively designed into new products.
lektor
embedded world Special 2022 15
