The 8-BIT Survival Syndrome, Part 1



As recently as the 1970s, a 4-bit word MCU, for example, the Intel 4004 would have handled critical tasks. The 4-bit microcontroller had staying power and found its way into many battery-powered devices. Until recently, in 2010 specific iterations were still in production i.e. Epson’s S1C060 and S1C63 families. Modern 4 BIT devices are a modern interpretation of an original device that has enhanced architecture, performance, and overall capabilities. The reason for this fortitude is that they are not the same devices that Grandad used or programmed 1 word at a time.

While 32BIT MCUs are getting all the attention, many embedded systems and products use 8-bit devices. Without risk to the longevity of a new design, selecting a low-pin count 8BIT MCU that integrates a few precision analog peripherals, configurable GPIO pins, serial interfaces, and a fast-data-bus architecture - you can get a lot done with a little device.

The same debate that had been occurring around the 4BIT’s successor has the 8BIT device competing against the 16BIT and 32BIT replacements.

8BIT low-pin-count (LPC) microcontrollers have taken advantage of process shrinks to improve their features and are now able to serve, and perform in more applications than ever before at lower cost. The core independent approach by Microchip is an example, where a peripheral can be configured and then perform a task or tasks in hardware with minimal interaction with the MCU core - this freeing up processing capability. The innovation seen in 8BIT devices ensures competitiveness against a 32BIT rival.

Hybrid systems are also more prevalent now where an 8BIT device handles delegated tasks requiring fewer resources or are lower priority.

While even LPC devices were becoming pad-limited by the 0.35μm technology node, advances in architecture, motor control, smart energy management, Ethernet, and wireless connectivity requirements for home automation and control have led to a new range of applications for 8-bit MCUs.

From the product scope perspective, the reasons why 8BIT devices are just not going away any time soon are the same reasons just over a decade ago 4BIT devices were still in production from the 1970s

Key performance and device enhancements are listed below as to where 8 BIT devices are continuing to innovate and either retain their established tole or enhance it.

Would you develop a system using a 4BIT device? No! You would most likely want to motivate the need to move with the times, considering if it's worthwhile for your team or company to move into that arena. However, could there be a niche opportunity?

Rather, should the application, the budget, or the system requirements meet the need . . . yes, you would consider it at the very least. There may also be a deep pockets client who has a warehouse of them and wants to use them.

The question we will answer along the way in this series is whether the 32BIT device is an application requirement. If not, then how best to leverage an existing or enhanced 8BIT device?

8BIT MCUs offer extensive on-chip integration that helps keep both costs and power consumption low — an ideal fit for today's market trends and applications. By providing low-cost solutions in small packages with integrated functions that meet a range of application-specific requirements, 8BIT MCUs provide competitive choices for systems that require high integration.

In the next segment, we compare the devices.

The 8-Bit Survival Syndrome, Part 2