What I did in 8-weeks-VSD Internship? On-chip PLL using Sky130

In this 8-week internship I spent the first week on researching existing work and making design decisions for the PLL components namely – Phase Frequency Detector, Charge Pump, Voltage Controlled Oscillator and Frequency Divider. I also looked into linking of the Sky130nm PDK with SPICE for the circuit implementation.

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India’s ESDM and World’s open-source vision

All the people whom you see in below image were a part of VSD 8-week Research IP design internship program, all interns are from colleges in India, and all of them built some cool analog IP’s from scratch. This internship program partially and unknowingly executes India’s ESDM vision and World’s open-source vision, all by college students, who passionately worked close to 14-15hours per day

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7th mile-stone in open-source analog IP design – 10-bit DAC

Ashutosh had joined our VSD Research IP design internship group 8-weeks back, along with 30 other interns. His journey on was from “I can’t, its too difficult” to “I did it”. Personally, only I know how hard it was for him when he saw an industry grade 10-bit DAC specifications on VSD IP website. We managed to achieve post-layout DNL of 3.5LSB and INL of 3.7LSB, which as per experience, is really tough for a fresher to achieve in a span of 8-weeks, but not impossible.

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2nd mile-stone in field open-source (open-lane EDA + Google/Sky130)

@Nickson joined our research project group under VSD Research internship program which runs for 8-weeks. He was supposed to develop flow for standard cell design and characterization using all open-source tools – magic/ngspice, then plug those standard cells into open-source PNR flow by open-lane, and benchmark RTL2GDS flow results. This needed a knowledge, not only of PNR, but device physics, custom layout, DRC/LVS and then (finally) Physical design/STA.

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VSD comes to MUMBAI on 19th February !!

As per huge request from students and working professionals from all over places, VSD is conducting another “VLSI SoC design workshop using open-source EDA tools” from 19th-23rd February, which has only 1-working day, and rest all are holidays. Below link has detailshttps://www.vlsisystemdesign.com/upcoming-event/

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Paper 3: Coverage Driven Functional Verification on RISC-V Cores

Design Verification is critical to proving functional correct- ness and establishing confidence in a design. Several stud- ies from industry and academia, particularly over the course of the last two decades, have explored various verifica- tion methodologies that fall somewhere between dynamic or purely static formal approaches.
System-on-Chips (SoCs) today have become extremely complex structures housing heavily optimized cores, count- less peripherals, and large interconnect fabrics. Even re- stricting ourselves to just verifying the microprocessor, the state space to be verified is enormous and cannot be exhaus- tively explored in any finite amount of time. Manually writ- ten tests, while effective at capturing some complexities of design intent, suffer from the fact that they are expensive in cost and time required to develop them. Random stimulus methods perform better because they eventually cover many cases. Most new ideas in dynamic verification over the last two decades have largely been towards semi formal verifi- cation methodologies such as coverage driven verification and constrained test generation. In this paper, we explore an approach to dynamic functional verification that we use at the RISE lab, IIT Madras for the verification of the RISC-V based Shakti cores.

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