[Reason 1] Processing speed is overwhelmingly faster than microcomputers

Although the performance of general microcontrollers has improved, their processing speed is still measured in microseconds.
Even low-end FPGAs are capable of processing in nanoseconds, and their processing speed is overwhelmingly faster than that of microcontrollers.

Since FPGAs perform processing in hardware, they excel at processing PWM and other processes required for motor control.

This is because the difference is several times to over 100 times faster than the processing speed of microcontroller software.

[Reason 2] Multiple motors can be processed simultaneously

There are an increasing number of situations where 10 or 20 motors must be controlled in a single application, such as in industrial equipment or factory automation robots.

Is it possible for a single microcontroller to handle all of this processing? It would be impossible to control 10 motors simultaneously.

In the first place, there are no microcontrollers that are equipped with the dozens of PWMs required for control.
However, with an FPGA, it is easy to install dozens of PWMs. In addition, since a CPU can be installed inside the FPGA, it is possible to control dozens of motors with a single FPGA.

[Reason 3] Long-term supply is possible

The biggest concern for manufacturers supplying industrial equipment applications is discontinuation of products.

If a microcontroller is discontinued, in most cases it means that your company's products will also be discontinued.

Unless we are provided with a very reliable successor microcontroller, we will not be able to continue production.

Altera® provides most of its FPGAs for a long time. Some products are still in production more than 20 years after they were first manufactured. If an FPGA is discontinued, you can easily port your design source to a successor FPGA.
This means that the same functionality will continue to be available on future FPGAs.

That said, if controlling one motor is sufficient, a microcontroller will suffice, and there are also disadvantages to using an FPGA.

[Disadvantage 1] Requires multiple power supplies for operation

A typical FPGA has separate core and I/0 power supplies.

For example, an FPGA requires a 1.2V core power supply, plus an I/O power supply for each interface.
Multiple power supplies are required for each interface, such as memory, differential signals, and LVCMOS.
One disadvantage of FPGAs is that the power supply design is more complicated than that of microcontrollers.
However, Altera®'s latest device, the MAX® 10 series, is also available as an FPGA that operates on a single 3.3V supply, and this disadvantage is gradually being eliminated.

[Disadvantage 2] Configuration ROM required

Since typical FPGAs are designed based on SRAM, the circuit data inside the FPGA is lost when the power is turned off. Therefore, the FPGA needs to be configured from an external ROM every time it is started.

This means that the FPGA requires a two-chip configuration, and the external ROM also increases costs.

However, Altera's latest device, the MAX® 10 series, has built-in flash memory within the FPGA, enabling FPGA operation on a single chip, eliminating this disadvantage.

[Disadvantage 3] High unit price compared to microcomputers

A while ago, FPGAs were priced at several thousand to several tens of thousands of yen per unit, which meant that they were often several times more expensive than microcontrollers.

However, with the advancement of process miniaturization, low-cost FPGAs are becoming more common. Depending on the quantity purchased, it is now possible to purchase an FPGA for motor control for just a few dollars.

As mentioned above, there are some disadvantages to using FPGAs for motor control compared to microcontrollers, but the latest Altera® FPGAs have eliminated these disadvantages.

FPGAs are increasingly being used to develop high-value-added applications that require the control of multiple motors.

FPGA Development Kit "DE10 Lite"

Daughter card "Servo Motor Kit"

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DE10-Lite Board
Servo Motor Kit

Manufacturer site/Other related links

Details of DE10-Lite Board
Details of the Servo Motor Kit
Learn more about MAX 10 FPGAs