Patent ID: 6311280
Filing Date: 2001-10-30
Classification: G06F,Y02D

Abstract:
A method for reducing power consumption in portable electronic devices that include digital signal processing of streaming realtime data with a vector processor, the method comprising:storing streaming realtime data in a dynamic random access memory (DRAM) core which is organized as n-rows by m-columns;transferring various particular rows of data to a fully-associative cache m-columns wide in response to prefetching flags included in particular instructions of a program software for said vector processor;circulating outputs from said vector processor as intermediate arguments through a load unit interposed between said vector processor and said cache in order to save power by not instigating a read or write cycle in said core;write-scrubbing said various particular rows of data in said fully-associative cache m-columns wide to said core in response to write-scrubbing flags included in particular instructions of a program software for said vector processor;for any vector processor read access, deciding if a read access involves data that is already in any row-line of said cache;if said data to be read is not in said row-line of said cache, deciding if said data currently in said row-line of said cache needs to be written-back or flushed to said core before new data is downloaded to it;if so, performing said write-back wherein a pulse of power will be used from a battery power supply during said write-back, and to save power such cycles are kept to a minimum;reading a row of data from said core to said row-line of said cache, wherein a pulse of power is used from said battery power supply during said core read access, and to save power these cycles too are kept to a minimum;marking said row in said core as being ""dirty"" due to an unavoidable destructive read that corrupted said row in said core; andserving up requested data.