====== EE6361: Advanced Topics in VLSI (Jan 2020) ====== ===== Instructors ===== * [[http://www.ee.iitm.ac.in/~janakiraman/|Janakiraman Viraraghavan]] (IITM) * Dr. Rahul Rao (STSM IBM. India. Pvt. Ltd, Adjunct Faculty IITM) ===== Classroom ===== ESB-207A ===== Schedule ===== T-slot - Friday (2:00 - 4:50 PM) ===== Evaluation ===== * Assignments: 10% * Mid Term: 30% * Project : 20% * End Semester Exam: 40% ===== Course Objective ===== (Why we teach this course?) * Introduce students to some relevant advanced topics of current interest in academia and industry * Give the students a feel for research topics * Make students aware of work happening in industries, specifically in India This course will cover three broad subjects: - SRAM design (Rahul Rao) - Embedded DRAM design (Janakiraman) - Emerging memories (PCM/ STT RAM) (Rahul + Janakiraman + Guest lecture) ===== Learning Objectives ===== (What the students should be able to do after the course) ==== Part 1- SRAM Design ==== * Articulate memory hierarchy and the value proposition of SRAMs in the memory chain + utilization in current processors * Explain SRAM building blocks and peripheral operations and memory architecture (with physical arrangement) * Articulate commonly used SRAM cells (6T vs 8T), their advantages and disadvantages * Explain the operation of a non-conventional SRAM cells, and their limitations * Explain commonly used assist methods * Explain how variations impact memory cells ==== Part 2- eDRAM Design and Yield Analysis ==== * Explain the working of a(n) (e)DRAM and what Embedded means? * Explain the working of a feedback sense amplifier and modify existing designs to improve performance * Calculate the voltage levels of operation of various components for an eDRAM * Introduce stacked protect devices to reduce voltage stress of the WL driver ===== Class 1 (17 Jan 2020) ===== * Memory hierarchy * Memory organization * Flip flop * 6T SRAM basics ===== Class 2 (24 Jan 2020) ===== * 6T SRAM cell * Static/ Read and Write noise margins * Read/ Write/ Hold and Access failures [[http://www.ee.iitm.ac.in/~janakiraman/courses/EE6361/Jan-2020/material/20200124_IITM_C1.pdf|Lecture Slides]] ===== Class 3 (31 Jan 2020) ===== * Memory Arrangement * Alternative Cell Types * Column interleaving * Memory Folding [[http://www.ee.iitm.ac.in/~janakiraman/courses/EE6361/Jan-2020/material/20200131_IITM_C2.pdf|Lecture Slides]] ===== Class 4 (7 Feb 2020) ===== * 8T SRAM Cell * Multi-port SRAM * Variations * Redundancy [[http://www.ee.iitm.ac.in/~janakiraman/courses/EE6361/Jan-2020/material/20200207_IITM_C3.pdf|Lecture Slides]] ===== Class 5 (14 Feb 2020) ===== * Redundancy * Assist Circuits * Multi VCC SRAM cells * Bias Temperature Instability [[http://www.ee.iitm.ac.in/~janakiraman/courses/EE6361/Jan-2020/material/20200214_IITM_C4.pdf|Lecture Slides]] ===== Class 6 (21 Feb 2020) ===== * BTI Failure * Hot Carrier Injection * Power * Fault Testing [[http://www.ee.iitm.ac.in/~janakiraman/courses/EE6361/Jan-2020/material/20200221_IITM_C5.pdf|Lecture Slides]] ===== Class 7 (28 Feb 2020) ===== * Variation Characterization * Array-Based IV characterization * Digital Characterization [[http://www.ee.iitm.ac.in/~janakiraman/courses/EE6361/Jan-2020/material/20200228_IITM_C6.pdf|Lecture Slides]] ===== Class 8 (6 Mar 2020) ===== * Variation Characterization * Critical Path Monitor * SRAM Fluctuation Monitor [[http://www.ee.iitm.ac.in/~janakiraman/courses/EE6361/Jan-2020/material/20200306_IITM_C7.pdf|Lecture Slides]] ===== Week 9 ===== * Basics of DRAM * Definition of Embedded * Requirement for short BLs in DRAMs * Transfer ratio * Retention time/ Refresh rate analysis * Power supplies required for eDRAM * Advantages of eDRAM over eSRAM [[http://www.ee.iitm.ac.in/~janakiraman/courses/EE6361/Jan-2020/material/ee6361-eDRAM-L1.pdf|Lecture Slides]] ===== Week 10 ===== * Write time calculation * Hierarchical sensing * 3T Micro Sense Amp * 3T Micro Sense Amp Noise Analysis Barth, J. et al., “A 500 MHz Random Cycle, 1.5 ns Latency, SOI Embedded DRAM Macro Featuring a Three-Transistor Micro Sense Amplifier,” IEEE JOURNAL OF SOLID-STATE CIRCUITS, VOL. 43, NO. 1, JANUARY 2008. [[http://ieeexplore.ieee.org/document/4443182/|PDF]] [[http://www.ee.iitm.ac.in/~janakiraman/courses/EE6361/Jan-2020/material/ee6361-eDRAM-L2.pdf|Lecture Slides]] ===== Week 11 ===== * 3T Micro Sense Amp - Evolution * 3T Micro Sense Amp - GSA * 3T Micro Sense Amp - DSA * Read Time Analysis * SOI Technology Problems [[http://www.ee.iitm.ac.in/~janakiraman/courses/EE6361/Jan-2020/material/ee6361-eDRAM-L3.pdf|Lecture Slides]] ===== Week 12 ===== Gated Feedback Sense Amplifier * Construction * Read and Refresh * Read Data Mux * Write G. Fredeman et al., "A 14 nm 1.1 Mb Embedded DRAM Macro With 1 ns Access," in IEEE Journal of Solid-State Circuits, vol. 51, no. 1, pp. 230-239, Jan. 2016. doi: 10.1109/JSSC.2015.2456873 [[https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=7210238|PDF]] [[http://www.ee.iitm.ac.in/~janakiraman/courses/EE6361/Jan-2020/material/ee6361-eDRAM-L4.pdf|Lecture Slides]] ===== Week 13 ===== * Variability study * Thick Oxide Word-line drivers * Thin Oxide Word-line drivers * Memory Testing [[http://www.ee.iitm.ac.in/~janakiraman/courses/EE6361/Jan-2020/material/EE6361-eDRAM-Janakiraman-2020.pdf|Consolidated Lecture Slides]]