# US 8,788,789 B2 · Power filter in data translation look-aside buffer based on an input linear address > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,788,789 B2 - Document ID: US8788789B2 - Status: Granted - Kind: B2 - Application number: 12/968,613 - Filed: 2010-12-15 - Published: 2012-06-21 - Granted: 2014-07-22 - Earliest claimed: 2010-12-15 - Assignees: Advanced Micro Devices, Inc. - Applicants: Deepika Kapil; David Hugh McIntyre - Inventors: Deepika Kapil; David Hugh McIntyre - Web page: https://patentgrep.com/patent/US8788789B2 ## CPC - G06F 12/1027: using associative or pseudo-associative address translation means, e.g. translation look-aside buffer [TLB] - G06F 2212/1028: Power efficiency - Y02D 10/00: Energy efficient computing, e.g. low power processors, power management or thermal management - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) - Y02D: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE ## Abstract A method and an apparatus for power filtering in a Translation Look-aside Buffer (TLB) are described. In the method and apparatus, power consumption reduction is achieved by suppressing physical address (PA) reads from random access memory (RAM) if the previously translated linear address (LA), or virtual address (VA), is the same as the currently requested LA. To provide the correct translation, the output of the TLB is maintained if the previously translated LA and the LA currently requested for translation are the same. ## Claims ### Claim 1 A method for reducing power consumption in memory address translation, the method comprising: maintaining a physical address (PA) corresponding to a previously translated linear address (LA) as an output if the previously translated LA is the same as a received LA; and suppressing reading of a PA corresponding to the received LA if the previously translated LA is the same as the received LA, wherein a reset clock signal is suppressed to maintain the PA. ### Claim 2 (depends on 1) The method of claim 1 wherein comparing the received LA with a previously translated LA comprises: delaying the previously translated LA by a clock cycle; comparing the previously translated LA with the received LA to determine if they are the same. ### Claim 3 (depends on 1) The method of claim 1, wherein a Static Random Access Memory (SRAM) is used for storing PA translations. ### Claim 4 (depends on 3) The method of claim 3, wherein the SRAM has dynamic pulldown read bitlines. ### Claim 5 (depends on 1) The method of claim 1, wherein LAs which are capable of being translated by the TLB are held in a content addressable memory (CAM). ### Claim 6 (depends on 5) The method of claim 5, wherein the CAM has an entry for every LA capable of being translated. ### Claim 7 (depends on 1) The method of claim 1, wherein memory address translation is performed by a Translation Look-aside Buffer (TLB). ### Claim 8 A memory address translation device comprising: circuitry configured to maintain a physical address (PA) corresponding to a previously translated linear address (LA) as an output if the previously translated LA is the same as a received LA: and circuitry configured to suppress reading of a PA corresponding to the received LA if the previously translated LA is the same as the received LA, wherein a reset clock signal is suppressed to maintain the PA. ### Claim 9 (depends on 8) The memory address translation device of claim 8 further comprising circuitry configured to store linear addresses (LAs) capable of being translated by the memory address translation device and circuitry configured to store physical address (PA) translations corresponding to the LAs. ### Claim 10 (depends on 8) The memory address translation device of claim 8 further comprising a content addressable memory (CAM) for storing linear addresses (LAs) capable of being translated and a random access memory (RAM) for storing physical address (PA) translations corresponding to the LAs. ### Claim 11 (depends on 10) The memory address translation device of claim 10, wherein the RAM is a Static Random Access Memory (SRAM) with dynamic pulldown read bitlines, and the CAM is an SRAM-type cell for storage with static match tree logic per entry. ### Claim 12 (depends on 8) The memory address translation device of claim 8 further comprising circuitry configured to delay the previously translated LA by a clock cycle and to compare the previously translated LA with received LA to determine if they are the same. ### Claim 13 A computer system comprising: a processor including circuitry configured to maintain a physical address (PA) corresponding to a previously translated linear address (LA) as an output if the previously translated LA is the same as a received LAI and circuitry configured to suppress reading of a PA corresponding to the received LA if the previously translated LA is the same as the received LA, wherein a reset clock signal is suppressed to maintain the PA. ### Claim 14 (depends on 13) The computer system of claim 13 further comprising a content addressable memory (CAM) for storing LAs capable of being translated and a random access memory (RAM) for storing PA translations corresponding to the LAs. ### Claim 15 (depends on 13) The computer system of claim 13 further comprising circuitry configured to delay the previously translated LA by a clock cycle and compare the previously translated LA with received LA to determine if they are the same. ### Claim 16 A non-transitory computer-readable storage medium storing a set of instructions for execution by one or more processors to reduce power consumption in a Translation Look-aside Buffer (TLB), the set of instructions comprising: a maintaining code segment for maintaining a physical address (PA) corresponding to a previously translated linear address (LA) as an output if the previously translated LA is the same as a received LA; and a suppressing code segment for suppressing reading of a PA corresponding to the received LA if the previously translated LA is the same as the received LA, wherein a reset clock signal is suppressed to maintain the PA. ### Claim 17 (depends on 16) The non-transitory computer readable storage medium of claim 16, wherein the set of instructions are hardware description language (HDL) instructions used for the manufacture of a device.