PERFECT Empower Project: Prototype Software Releases

PI: Massoud PedramCo-PIs: Murali Annavaram and Kaushik Roy

(Purdue)

July 17, 2014

DARPA Perfect Releases: Overview• Device Releases (nominal devices)

• 5nm gate length FinFET devices (7nm effective channel length) from Prof. Kaushik Roy’s group)

• 7nm gate length FinFET devices (10nm effective channel length) with two threshold voltages

• 14nm bulk CMOS devices• Cell Library Releases

• 5nm gate length FinFET cell libraries for near- and super-threshold operations

• 7nm gate length FinFET cell libraries with two threshold voltages for near- and super-threshold operations

• 14nm CMOS cell libraries for near- and super-threshold operations• 16nm CMOS (PTM) cell libraries for near- and super-threshold

operations• Architecture-level Releases

• PCACTI

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Device Releases: 5nm Gate Length FinFET• 5nm gate length (7nm channel length) FinFET devices

• SPICE-compatible Verilog-A models• Based on NEMO5 simulator, which uses quantum transport

models (e.g., atomistic simulator)• Three different device models depending on the degree of gate

underlap• The most advanced device model in the release• Available on the PERFECT Wiki site and NanoHub

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Device Releases: 7nm Gate Length FinFET• 7nm gate length (10nm channel length) FinFET devices

with two different threshold voltages• SPICE-compatible Verilog-A models• Includes low-threshold FinFET devices with a threshold voltage

of 0.2V-0.25V as well as high-threshold devices with a threshold voltage of 0.3V-0.35V

• Based on Synopsys TCAD suite (i.e., Sentaurus), which uses semi-classical transport models with quantum correction

• Beta release available on the PERFECT Wiki site and http://atrak.usc.edu/downloads/packages/

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Device Releases: 14nm CMOS Devices• 14nm CMOS devices developed by Prof. Pedram’s team

• SPICE-compatible Verilog-A models• Based on Synopsys TCAD suite (i.e., Sentaurus)• Beta release available on the PERFECT Wiki site and

http://atrak.usc.edu/downloads/packages/• May be compared with the PTM 16nm bulk CMOS device

models of Prof. Yu Cao’s team at Arizona State University

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Device Releases: Ongoing Work• The beta releases of 5nm gate length and 7nm gate

length FinFET devices are nominal device models• No accounting for the process variation effects yet• Nominal device model parameters may have to be changed in

order to do proper design centering• Must develop new models for a few critical corners

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Cell Library Releases: 5nm Gate Length FinFET

• Standard cell libraries based on 5nm gate length (7nm channel length) FinFET devices• Can be used for circuit synthesis• Beta release available on the PERFECT Wiki site and

http://atrak.usc.edu/downloads/packages/• Containing the following libraries:

• 5nm gate length FinFET library operating at 0.3V supply voltage level (near-threshold operation)

• 5nm gate length FinFET library operating at 0.45V supply voltage level (super-threshold operation)

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Cell Library Releases: 7nm Gate Length FinFET

• Standard cell libraries based on multi-threshold 7nm gate length (10nm channel length) FinFET devices• Beta release available on the PERFECT Wiki site and

http://atrak.usc.edu/downloads/packages/• Containing the following libraries:

• FinFET_7nm_HVT_0300.lib: Standard cell library of high-threshold FinFET devices operating at 0.3V supply voltage level (near-threshold)

• FinFET_7nm_HVT_0450.lib: Standard cell library of high-threshold FinFET devices operating at 0.45V supply voltage level (super-threshold)

• FinFET_7nm_LVT_0300.lib: Standard cell library of low-threshold FinFET devices operating at 0.3V supply voltage level (near-threshold)

• FinFET_7nm_LVT_0450.lib: Standard cell library of low-threshold FinFET devices operating at 0.45V supply voltage level (super-threshold)

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Cell Library Releases: 14nm and 16nm CMOS

• Standard cell libraries based on 14nm CMOS devices• Containing the following libraries:

• 14nm CMOS library at 0.55V supply voltage level (near-threshold operation)• 14nm CMOS library at 0.70V supply voltage level (super-threshold

operation)• 14nm CMOS library at 0.80V supply voltage level (performance-boosted

operation)• Standard cell libraries based on 16nm PTM CMOS

devices• Containing the following libraries:

• 16nm CMOS library at 0.50V supply voltage level (near-threshold operation)• 16nm CMOS library at 0.70V supply voltage level (super-threshold

operation)

• Beta release available on the PERFECT Wiki site and http://atrak.usc.edu/downloads/packages/

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Cell Library Releases: Ongoing Work• Incorporating wire load modeling in the standard cell

library• Wire load library will be released soon

• Generating (l-based) physical cells for layout

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Architecture-level Releases: PCACTI• PCACTI: A delay, power, and area modeling tool for

cache and memory systems for deeply-scaled FinFET devices supporting multiple voltage regimes• Extension over the widely-used CACTI tool for bulk CMOS

devices• Addresses key shortcomings of current releases of CACTI:

• Support only planar CMOS devices from 90nm to 22nm technology nodes• Rely on outdated (and somewhat inaccurate) technological parameters

– Extracted from 2005 ITRS predictions• Support only conventional 6T SRAM cell designs

– An 6T SRAM cell optimized for 130nm process is adopted for all technology nodes

– The impact of VDD scaling and device mismatches have been ignored

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PCACTI: Novel Features• Features of PCACTI (previously named FinCACTI):

• Accurate technology parameters for deeply-scaled (7nm gate length) FinFET devices

• ON/OFF currents for N- and P-type fins (for temperatures ranging from 300K to 400K)• SPICE-compatible Verilog-A models to derive gate- and circuit-level

parameters• E.g., PMOS to NMOS size ratio, stack effect factor, DC noise margin of FinFET-based

SRAM cells• Accurate area and capacitance models for FinFET devices• Layout area, power, and access delay calculations for FinFET-based 6T

and 8T SRAM cells• Architectural support for the 8T SRAM cells• Multiple voltage support for SRAM cells• Updated interconnect-related electrical parameters

• Based on 2012 version of the ITRS• XML-based interfaces for specifying cache configuration, SRAM cell,

technological parameters, etc.

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PCACTI: Status and Near-Future Plans• Current version supports 7nm gate length FinFET devices (low

threshold device), 14nm CMOS devices (our model), and 16nm PTM CMOS devices

• Supports two operating voltage levels (near- and super-threshold) for each technology node

• In the process of adding support for 22nm and 32nm CMOS devices for completeness as well as various versions of the 5nm gate length FinFET devices

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PCACTI: Releases, Reference, Results• Releases of PCACTI under the PERFECT Wiki page and

http://atrak.usc.edu/downloads/packages/ • PCACTI.zip file for download and web interface

• Reference:• A. Shafaei, Y. Wang, X. Lin, and M. Pedram, “FinCACTI: Architectural analysis

and modeling of caches with deeply-scaled FinFET devices,” Proc. of the IEEE Computer Society Annual Symposium on VLSI, July 2014, Best paper award.

• Sample Results for a 16KB, 4-way set-associative, L1 cache• 7nm gate length FinFET (our device design) at VDD = 0.3V and VDD = 0.45V• 14nm CMOS (our device design) at VDD = 0.55V and VDD = 0.8V

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PCACTI: Web Interface

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Longer Term Plans for PCACTI• Planned work:

• Enhancing SRAM cell stability and reduce leakage:• FinFET-based SRAM cells with multi-threshold devices• FinFET-based SRAM cells dual-gate control capability

• Performing variability-aware design of SRAM cells: Joint optimization of VDD and SRAM cell configuration

• Start using new models provided by PCACTI along with architectural modeling and simulation tools such as GPUWattch and McPAT for doing power/performance characterizations and optimizations at the architecture and system levels

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