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

HVAC Control in the New Millenniumcapture that state and save it for later use. Xilinx 62xx series FPGAsuse a 32-bit data bus called the FastMAP processor interface. It allowsthe internal state of the FPGA to be read and written like memoryand makes it possible to swap logic designs in much the same waythat pages of virtual memory are swapped into and out of physicalmemory.Hardware ObjectsA hardware object is a functional or logical hardware componentthat contains its own configuration and state information. It is a pieceof logic that can be executed in an RPU. Hardware objects arerelocatable and can be executed from any position in the chip.These relocatable logic blocks have some constraints based onthe hardware page size. Page sizes of 4 and 16 gates are used in theXilinx 62xx series of FPGAs because of the routing resources at theintersections. This makes routing between hardware objects or a hardwareobject and its I/O pins much easier. By standardizing the interfacesof hardware objects, it is possible to maintain libraries of frequentlyused objects and to quickly build larger designs from thesesmaller components.Hardware objects that interface to the world outside the RPU doso through an abstraction. This abstraction is called a hardware objectframework which is a ring of logic in the RPU that is physically locatedalong the outer edges. This provides a set of standard interfacesto memory and peripheral devices outside of the RPU.In reconfigurable computing the software decides which hardwareobjects to execute and when to swap hardware objects into andout of the reconfigurable logic. It also performs the routing betweenhardware objects or between hardware objects and the hardware objectframework.The software that does this is called the run-time environmentand is similar to the operating system that manages the execution ofmultiple tasks in personal computers. Hardware objects have prioritiesand it is the job of the run-time environment to organize this informationand make decisions based upon it.The run-time environment is needed to make decisions whilethe system is running. The input data and the appropriate logic block©2001 by The Fairmont Press, Inc. All rights reserved.