HVAC Control in the New Millennium.pdf - HVAC.Amickracing

Control Technology, Microelectronics and Nanotechnologyare handed over to the run-time environment which executes the attachedhardware object.The run-time environment must first locate space within theRPU that is large enough to execute the hardware object. It then performsthe necessary routing between the hardware object’s inputs andoutputs and the blocks of memory needed. Commercial run-time environmentsfor RPUs will emerge if reconfigurable computing becomespopular.The run-time environment can be thought of as a series of threelayers. The device abstraction layer is the lowest level and is analogousto the parts of an operating system that must be written in assemblylanguage because they are processor-specific. The device abstractionlayer is concerned with the hardware page size and therouting resources that are available at the edge of each hardwarepage. The device abstraction layer also provides the read/write interfacefor the layer above.The middle layer controls the placement and routing of hardwareobjects. It decides where each object will be physically locatedwithin the device and adds routing between hardware objects.The upper layer is called the object scheduler. It provides an applicationprogramming interface (API) for the RPUs and is responsiblefor deciding which hardware objects are currently running. Thisdecision can be based on a scheduling algorithm such as first-come,first-served.ReferencesBarr, Michael, “A Reconfigurable Computing Primer,” Multimedia SystemsDesign, Vol. 2 No. 9, September 1998, pp. 44-47.Buderi, Robert, “Sleep with a Computer,” Upside, Vol. 118 No. 1, February2000, p. 202.Crowley, Susan I., “Hello to our Future,” AARP Bulletin, Vol. 41 No.1, January 2000, pp. 3, 14-15, 20.Keenan, Robert, “Modem Monitors SCADA Systems,” Wireless SystemsDesigns, Vol. 2 No. 5, May 1997, p. 30.Keenan, Robert, “Wireless System Secures Shopping Malls,”WirelessSystems Design, Vol. 2 No. 4, April 1997, p. 30.Liptak, Bela A., Editor-in-chief, Instrument Engineers’ Handbook, 3rd©2001 by The Fairmont Press, Inc. All rights reserved.