The 8-Bit Survival Syndrome, Part 2
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Just like the 4BIT pre-microcontroller, the 8 BIT MCU has been finding ways to stick around. They can get the same work done, and have improving features and speeds offering competitive reasons to work with them.
Moving ahead with the 16 and 32-bit future may have meant that a manufacturer left their 8-bit options fall from their catalog. The net result is that those who kept up with their 8BIT product line, have a competing product for 32BIT rivals.
Competing, you may wonder? While it's true that a 32BIT microcontroller is fully capable of doing anything an 8BIT can do, can it perform with the same efficiency and cost-effectiveness? Maybeโฆ
The advantage that an 8BIT has is that you only have to manipulate a small amount of data for a PORT to be configured or read. 8BIT devices are ideally suited and designed to interface with systems and devices that have simple input. Switches, sensors, keyboards, small displays, and serial devices.
Adding intelligence to a simple home appliance is the proverbial sweet spot for an 8BIT device, as the end product needs to be inexpensive, easy to use and to ensure that the product has a slight edge, custom or purpose-built. Moving from the planning perspective and onto the more technical scope, the following aspects of an 8BIT design trump the 16 or 32BIT equivalent.
- Code density for an 8BIT device is much smaller
- 8BIT Microcontrollers have a wider operating voltage from 1.8Vdc to 5.5Vdc, whereas even with 5-volt tolerant inputs, the operating range of the 16BIT or 32BIT is restricted to <3.3VDC
- 8BIT devices are more tolerant of noisy environments
- 8BIT devices are more power efficient, whereas since the 32BIT device is optimized for higher frequencies their power consumption is higher
In general, the 32-bit microcontrollers are a better fit for applications that have a machine interface with calculation performance and software-centric designs with an RTOS or multi-tasking โ so your higher performance applications.
Does your application meet or have the following requirements: โข Hardware-centric applications โข Deterministic behavior, โข Low sleep power consumption, โข Robust electrical characteristics, and a real-world interface,
If the above is your application, the 8-bit microcontroller is still the best technical solution. This is apt for applications such as desktop coffee machines, toasters, key fobs, security tokens, security system sensors, toothbrushes, PC fan controllers, thermostats, and thousands of other applications.
Part 3 we sum it up.
