There is a great deal of public and political enthusiasm for hybrid electric vehicles.  This is founded on the idea, no doubt true, that hybrid electric vehicles can reduce gasoline consumption and dependence on imported oil in the United States.  But are they the best short term solution?   In the summer of 2008 when gasoline exceeded four dollars per gallon in the U.S., there was a surge of interest in smaller, more fuel efficient cars and hybrid electric cars.  Gasoline prices have returned to about two dollars a gallon, but many consumers now believe it is only a matter of time before prices go up again.  Previous gasoline crises, however, have shown that consumers have a very short memory for pain.  Based on past behavior, there is a good possibility that consumers will return to larger cars, pickup trucks and SUVs if gasoline prices stay low for three or four years.  To be ready for that possibility and still be able to reduce pollution and dependence on foreign oil, it is essential that those vehicles have better fuel mileage.   There are several emerging technologies that can significantly improve the efficiency of gasoline engines in the short term: gasoline direct injection; dual clutch transmissions; electronic valves and electrically powered auxiliaries for example.  Together these technologies could improve gasoline mileage by 15% to 25%.  The engineering investment to bring these technologies to market is much less than the investment needed to further develop hybrid electric cars.  Cars with more efficient gasoline engines will cost less than hybrid electric cars; and the automobile companies will make a profit on them, which many believe will not be achievable for hybrid electric vehicles for five to ten years.   As pointed out in the recently published Semico study MA102-09 titled, “Hybrid Vehicle Electronic Control: Keeping the Current Going,” hybrid vehicles will be a very good opportunity for the semiconductor industry.  The revenue for semiconductors used in hybrid electric vehicle control systems will triple from 2008 through 2013.  Semico believes that hybrid electric car development should be continued, but there are practical problems.   

Automobile companies worldwide are having financial problems.  They are short on cash and losing money so badly that some are in danger of bankruptcy.  It is going to be difficult to find engineering development money.  Although hybrid electric vehicles may be a better long-term solution to gasoline consumption and pollution problems, Semico believes that improving gasoline engine efficiency should have priority in the short term.  It promises quicker results for less investment by the auto companies, while their available engineering development dollars are severely pinched.  The semiconductor industry wins in either case because most of the technologies necessary to improve vehicle efficiency will require some form of electronic control. 

Morry Marshall

Senior Automotive Analyst

 The wiring harness for in-vehicle entertainment is becoming increasingly complex.  Only a few years ago the only electronic entertainment device in a car was the radio.  Today, an infotainment system may include an FM radio, a satellite receiver, a CD or DVD player, an amplifier, multiple speakers, a telephone, a navigation unit, an MP3 input and one or more displays.  Tomorrow, a vehicle may contain all of the above plus a wireless connection to the internet.  The wiring for an FM/AM radio with two speakers in the dash was simple.  The wiring for a modern infotainment system is not.  What to do?

The answer is a multiplexing, but older automotive multiplexing standards, such as CAN (Controller Area Network), do not have enough bandwidth for multimedia applications.  Fortunately, a standard developed specifically for multiplexing infotainment systems is readily available.  Audi, BMW, Daimler, Harman/Becker and SMSC developed the MOST (Media Oriented Systems Transport) standard and later founded the MOST Cooperation to further refine and enhance it. They are the Partners and Steering Committee of the organization.  MOST was originally developed in response to several European companies’ recognition of their need for a common infotainment multiplexing solution. Thirteen other car manufacturers and more than seventy automotive suppliers are Associated Partners.  The original standard, MOST25, is being used by car manufacturers from Europe, Japan and Korea.  The software infrastructure is also currently being used in one vehicle manufactured in the US, the Dodge Ram pickup truck. 

The complete technical details of MOST25 are beyond the scope of this article, but they are available on the MOST Cooperation Web site, (www.mostcooperation.com).  Basically, the standard provides for synchronous cyclic continuous repetition of MOST frames on a ring network.  Each frame is divided into a control channel, one or more synchronous channels and a packet/ethernet channel.  The timing is provided by one master device.  The primary purpose is to transmit audio or video signals at a premium quality level.   In a typical application, a MOST25 network can reduce the wiring harness weight by as much as 3 ½ pounds, the total length of wires needed by as much as 90 feet and the number of contacts needed from nearly forty to less than ten.  This is a savings in weight, cost and complexity. 

An evolutionary path is available. The latest generation, MOST150, provides a bandwidth of 150Mbs.  It doubles the bandwidth of the synchronous MOST25 channels, adds isochronous channels and adds a channel for Ethernet data transmission. With connections to the Internet, it is ready for the car of tomorrow. MOST 150 uses the same API’s as MOST25 so MOST25 applications can be migrated with little change.

Semico Spin

Multiplexing the infotainment devices in a vehicle has obvious advantages.  MOST25 and MOST150 are multiplexing standards that have been designed specifically for this application.  Any automobile manufacturer moving toward infotainment multiplexing should look no further than these standards.  Semiconductor manufacturers should be aware of the standards and helping to make them a universally accepted solution.