DETROIT – The auto industry cannot afford to have microprocessors on vehicles dedicated to only one function.
So saidTeves AG & Co. CEO Karl-Thomas Neumann in a panel discussion at the Convergence 2006 Transportation Electronics Conference earlier this week.
“This is not going to be possible if for every function we bring into a car, we add another sensor,” Newmann said at the time. “No, we have to reuse functionality. For that camera sensor we have in our cars, we need to use that sensor for multiple applications.”
As if on cue, Freescale Semiconductor Inc., which has shipped 17 billion embedded devices and claims market leadership for automotive integrated circuits, demonstrates at Convergence a 32-bit microcontroller with dual functionality.
For instance, an instrument panel typically has up to five electronic control units (ECUs), each dedicated to a different component, such as climate control, lighting, audio, instrumentation and navigation.
Freescale, based in Austin, TX, says its new MPC5510 family of microcontrollers could eliminate some of those ECUs by combining two functions on one chip.
The only restriction is the functions need to be located near each other in the vehicle. For instance, one microcontroller could govern both seat controls and door locks.
Auto makers desperately want to reduce the number of ECUs in vehicles without sacrificing performance and convenience. Eliminating one ECU saves the cost of a circuit board; a set of connectors; software; and a microcontroller, which acts as the brain of the device.
Freescale expects its dual-core 32-bit processor to represent savings for auto makers, but the company says ECU contracts are too unique to estimate overall potential cost savings.
In addition to governing two separate vehicle functions, the MPC5510 microcontroller could act as a failsafe mechanism. While one half of the chip could manage the functionality of, for instance, an antilock brake module, the other half could check the computer calculations to ensure they match up with the driver’s intent.
“There’s always an opportunity for a calculation error,” says Ray Cornyn, Freescale’s manager-global automotive products operation. “This is an opportunity for a device to be sure you’ve made the right decision.”
Cornyn says Freescale has a signed contract for the MPC5510 microcontroller for a vehicle arriving in Europe in 2009. The chip also supports new in-vehicle communications protocols, such as FlexRay.
Automotive microcontrollers have added processing power since they first arrived in the late 1970s. Cornyn says Freescale’s first automotive ECU, integrating an 8-bit processor, was designed to control engine spark and timing, resulting in greatly reduced emissions in 1978.
By the late 1980s, higher-speed 16-bit processors were governing ECUs for antilock brakes, and even faster 32-bit processors arrived in the mid-1990s for engine, navigation and brake control, Cornyn says.
Today, 32-bit controllers are used widely to manage powertrain, infotainment, navigation, chassis control and airbag functions. But 32-bit controllers have not taken over.
The average vehicle in North America has about 50 ECUs, and the vast majority of those employ 8- and 16-bit processors, says Manuel Alves, Freescale product marketer.
Alves estimates five of the 50 ECUs have 32-bit processing capability.
Higher processing speed, however, does not always translate into higher cost for a microcontroller.
Some of the company’s 16-bit controllers are less expensive than certain 8-bit controllers, while others are more expensive than 32-bit devices, he says.
Also at Convergence, Freescale demonstrates a tire-pressure monitoring system that meets requirements of the National Highway Traffic Safety Admin.
The system, which will appear on a production vehicle in 2008, deploys one sensor at each wheel that directly measures air pressure and temperature. If the sensors detect loss of air pressure, they send a signal to a central controller, which alerts the driver.