Powerful 32-bit microcontrollers often manage new features and functions, but the market for simple 8-bit controllers is holding up nicely. These devices give design teams the flexibility to get to market quickly with inexpensive modules that use little power.
STMicroelectronics has expanded its 8-bit automotive-grade microcontroller portfolio with compact, inexpensive devices that run at 20 MIPS. The CPUs also offer connectivity, timing, and analog functions for applications such as seat controllers, window lifters, HVAC controls and gateways, as well as under-the-hood systems.
Applications like these are keeping demand for simple controllers high. Tom Hackenberg, Principal MCU Analyst for IHS Technology, said 8-bit CPUs accounted for 24% of the automotive microcontroller market last year. He predicts that 8-bit chips will decline only slightly in 2018, dropping to 22%.
“Companies like Microchip, Renesas, NXP, Atmel, Freescale, Cypress, Infineon, Silicon Labs, STMicro, and many others have continued to advance the power efficiency and integration features of 8-bit solutions to keep this market thriving for the foreseeable future,” Hackenberg said.
Chip marketers and analysts explain that there are many applications where the sub-$1 price of 8-bit chips is only one of their attractive features. With more and more electronics in vehicles, engineers see many reasons to deploy the small devices.
“They offer low pricing, small packages, and low power consumption,” said Christophe Loiodice, Product Line Manager at STMicroelectronics. “More and more mechanical systems are being replaced by electronic applications. Time-to-market is very important, so many engineers pick 8-bit chips because they’re easy to use. The tasks don’t need a lot of software, so large memory sizes aren’t important.”
New regulations are also helping fuel demand for simple chips. In the U.S., rear-view cameras are being mandated, opening up a new high-volume market.
“Developers want small packages; often a rear-view camera’s printed circuit board is only 2 mm square,” Loiodice said. “These applications also need low power; automakers want solutions that help them reduce power consumption.”
Hackenberg predicts that 32-bit CPUs will soon account for more than half the automotive CPU sales, but he sees many new roles for 8-bit chips.
“As more nodes share their operational status, sensor data, or other information, most of the controllers will only need basic modes—basically waking, transmitting, and going back to standby,” he said. “They’ll also see use with small motors that do nothing but infrequently readjust a seat or window position. The 8-bit market will benefit strongly from new power/price-sensitive Internet of things connectivity.”
Even as these simple systems evolve, they aren’t expected to migrate up to 16-bit CPUs. As 32-bit CPU pricing declines and 8-bit capabilities rise, they’re squeezing out 16-bit chips. Hackenberg predicts that 16-bit usage will shrink from 31% last year to 23% in 2018.
Loiodice noted that STMicro hasn’t introduced a 16-bit chip since 2009. He said that the drive to make cabins more comfortable and increase options for drivers and passengers is also helping maintain demand for these chips.
“If you use dedicated 8-bit controllers, it’s much cheaper to replace a module for one function than to replace one multi-function controller,” Loiodice said. “Another factor is that not all modules in the dashboard are made by one company. The Tier 1s use small, inexpensive controllers for each module.”