DSP, Micros & Memory


The 8-bit survival syndrome – Part 2

30 April 2024 DSP, Micros & Memory

Just like the 4-bit pre-microcontroller, the 8-bit MCU has been finding ways to stick around. Their features and speeds have been improving offering competitive reasons to work with them. Moving ahead with the 16- and 32-bit future may have meant that a manufacturer let their 8-bit options fall from their catalogue. The net result is that those who kept up with their 8-bit product line, have a competing product for 32-bit rivals.

Competing, you may wonder? While it’s true that a 32-bit microcontroller is fully capable of doing anything an 8-bit can do, can it perform with the same efficiency and cost-effectiveness? This depends…

The 8-bit advantage

The advantage that an 8-bit MCU has is that you only need to manipulate a small amount of data for a port to be configured or read. 8-bit 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 8-bit device, as the end product needs to be inexpensive, easy to use, and has a slight edge, custom or purpose-built. Moving from the planning perspective and onto the more technical scope, the following aspects of an 8-bit design trump the 16- or 32-bit equivalent:

• Code density for an 8-bit device is much smaller.

• 8-bit microcontrollers have a wider operating voltage from 1,8 to 5,5 V DC, whereas even with 5 V tolerant inputs, the operating range of the 16-bit or 32-bit is restricted to below 3,3 V.

• 8-bit devices are more tolerant of noisy environments.

• 8-bit devices are usually more power efficient.

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. That is, they are more suited to your higher-performance applications.

However, if your application meets the following requirements, then an 8-bit MCU should be on your radar and could still be the best technical solution:

• Hardware-centric applications;

• Deterministic behaviour;

• Low sleep power consumption;

• Robust electrical characteristics, and a real-world interface.

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.

The 8-bit Harvard architecture advantage

There are several advantages to using this architecture. The modified architecture uses a dual-bus arrangement, with data on the one and instructions on the other. This design executes instructions in a single cycle. The two-stage pipelining executes one cycle, while the next one is being accessed. This combination of architectural efficiency and ease of use enables designers to be more efficient and get more done using a PIC MCU.

An ongoing advantage is that you can migrate from one PIC MCU to another when requirements change. Using the commonly used peripherals and pinouts, and migrating a project from six to 100 pins and from 128 kB to 384 kB.

Conclusion

While the debate on 8-bit relevancy will be ongoing, the fight is between the popularity of the 32-bit devices vs the advantages an 8-bit device continues to offer. With the world moving ahead, and the tools for 32-bit development being either free or open-source, the 32-bit devices available are fully capable of replacing the 8-bits. However, 8-bit devices will put up a fight.

Ultimately, 8-bit devices handle hardware-centric applications better, and 32-bit devices handle the user interface, RTOS, or advanced applications with greater ease. And therein lies the answer. They don’t necessarily replace, but rather complement each other, and this is more evident in diverse applications that are complete systems. In single stand-alone applications, the 8-bit can supplant a 32-bit with the same ease that the 32-bit device supplants the 8-bit. Build a scaled system with delegated elements and the need for both 32-bit and 8-bit modules becomes apparent. 8-bit devices introduce scaled or delegated application capacity, cost-effectiveness, ease of use, and reduced programming complexity or density. The 32-bit devices are a better fit for applications that have a machine interface with high-performance requirements.




Share this article:
Share via emailShare via LinkedInPrint this page

Further reading:

MCU for noisy environments
EBV Electrolink DSP, Micros & Memory
The MCX?E24X is a high-performance microcontroller family from NXP, engineered for industrial, automotive-like, and energy-focused environments.

Read more...
SmartRAID 4300 Series
Altron Arrow DSP, Micros & Memory
Microchip’s disaggregated architecture leverages host CPU and PCIe infrastructure to overcome traditional storage bottlenecks in scalable, secure NVMe RAID storage solutions.

Read more...
High-performance SDR range
RFiber Solutions DSP, Micros & Memory
Epiq Solutions offers high-performance RF tuners and software-defined radios with various specifications for diverse applications in congested environments.

Read more...
High performance SDR design considerations
RFiber Solutions Editor's Choice DSP, Micros & Memory
As the spectrum gets increasingly crowded, and adversaries more capable, the task of examining wide bands and making sense of it all, while not missing anything, gets harder.

Read more...
Direct RF converters and FPGAs boost EW applications
RFiber Solutions DSP, Micros & Memory
The latest boost to electronic warfare designs comes from emerging FPGA architectures that combine advanced RF converters and high-performance processing engines in a single package.

Read more...
1-Wire EEPROM with secure authenticator
Altron Arrow DSP, Micros & Memory
The DS28E54 secure authenticator combines FIPS 202-compliant secure hash algorithm (SHA-3) challenge and response authentication with secured electrically erasable programmable read-only memory.

Read more...
Microchip enhances digital signal controller lineup
Future Electronics DSP, Micros & Memory
Microchip Technology has added the dsPIC33AK512MPS512 and dsPIC33AK512MC510 Digital Signal Controller families to its dsPIC33A DSC product line.

Read more...
MCX C Series development board
Avnet Silica DSP, Micros & Memory
The FRDM-MCXC444 is a compact and scalable development board for rapid prototyping of MCX C444 MCU from NXP Semiconductors.

Read more...
Redefining entry-level MCUs
NuVision Electronics DSP, Micros & Memory
The company positions the GD32C231 series as a ‘high-performance entry-level’ solution designed to offer more competitive options for multiple applications.

Read more...
Microchip enhances TrustMANAGER platform
Altron Arrow DSP, Micros & Memory
Firmware over-the-air updates and remote cryptographic key management provide scalable solutions for addressing IoT security challenges.

Read more...









While every effort has been made to ensure the accuracy of the information contained herein, the publisher and its agents cannot be held responsible for any errors contained, or any loss incurred as a result. Articles published do not necessarily reflect the views of the publishers. The editor reserves the right to alter or cut copy. Articles submitted are deemed to have been cleared for publication. Advertisements and company contact details are published as provided by the advertiser. Technews Publishing (Pty) Ltd cannot be held responsible for the accuracy or veracity of supplied material.




© Technews Publishing (Pty) Ltd | All Rights Reserved