Accelerating Cache Coherence Verification

Accelerating Cache Coherence Verification
by Bernard Murphy on 04-29-2021 at 6:00 am

Cache coherence checking min

It would be nice if there were a pre-packaged set of assertions which could formally check all aspects of cache coherence in an SoC. In fact, formal checks do a very nice job for the control aspects of a coherent network. But that covers only one part of the cache coherence verification task. Dataflow checks are just as important, where… Read More


Cache Coherence Everywhere may be Easier Than you Think

Cache Coherence Everywhere may be Easier Than you Think
by Bernard Murphy on 10-25-2020 at 10:00 am

Heterogenous cache coherence min

I attended one of the Arm partner events in Cambridge many years ago, when they first talked about the coherent hub for managing cache coherence. I was impressed, but the obvious question even then was how any non-Arm IP was going to hook into this hub. They had a solution, of course, the ACE interface, and I left satisfied. As is the … Read More


Quick Error Detection. Innovation in Verification

Quick Error Detection. Innovation in Verification
by Bernard Murphy on 08-27-2020 at 6:00 am

innovation min

Can we detect bugs in post- and pre-silicon testing where we can drastically reduce latency between root-cause and effect? Quick error detection can. Paul Cunningham (GM, Verification at Cadence), Jim Hogan and I continue our series on novel research ideas. Feel free to comment.

The Innovation

This month’s pick is Logic Bug DetectionRead More


Trends in AI and Safety for Cars

Trends in AI and Safety for Cars
by Bernard Murphy on 03-03-2020 at 6:00 am

AI at the Edge

The potential for AI in cars, whether for driver assistance or full autonomy, has been trumpeted everywhere and continues to grow. Within the car we have vision, radar and ultrasonic sensors to detect obstacles in front, behind and to the side of the car. Outside the car, V2x promises to share real-time information between vehicles… Read More


Verification, RISC-V and Extensibility

Verification, RISC-V and Extensibility
by Bernard Murphy on 02-05-2020 at 6:00 am

RISC-V

RISC-V is obviously making progress. Independent of licensee signups and new technical offerings, the simple fact that Arm is responding – in fundamental changes to their licensing model and in allowing custom user extensions to the instruction set – is proof enough that they see a real competitive threat from RISC-V.

Which all… Read More


How Should I Cache Thee? Let Me Count the Ways

How Should I Cache Thee? Let Me Count the Ways
by Bernard Murphy on 09-25-2019 at 5:00 am

cache hierarchy

Caching intent largely hasn’t changed since we started using the concept – to reduce average latency in memory accesses and to reduce average power consumption in off-chip reads and writes. The architecture started out simple enough, a small memory close to a processor, holding most-recently accessed instructions and data … Read More


Tutorial on Advanced Formal: NVIDIA and Qualcomm

Tutorial on Advanced Formal: NVIDIA and Qualcomm
by Bernard Murphy on 04-03-2018 at 7:00 am

I recently posted a blog on the first half of a tutorial Synopsys hosted at DVCon (2018). This blog covers the second half of that 3½ hour event (so you can see why I didn’t jam it all into one blog :D. The general theme was on advanced use models, the first half covering use of invariants and induction and views from a Samsung expert on efficient… Read More


Connecting Coherence

Connecting Coherence
by Bernard Murphy on 02-27-2018 at 7:00 am

If a CPU or CPU cluster in an SoC is the brain of an SoC, then the interconnect is the rest of the central nervous system, connecting all the other processing and IO functions to that brain. This interconnect must enable these functions to communicate with the brain, with multiple types of memory, and with each other as quickly and predictably… Read More


Cache Coherent Systems Get a Boost from New Technology

Cache Coherent Systems Get a Boost from New Technology
by Tom Simon on 05-20-2016 at 12:00 pm

The speed and power penalties for accessing system RAM affect everything from artificial intelligence platforms to IoT sensor nodes. There is a huge power and performance overhead when the various IP blocks in an SOC need to go to DRAM. Memory caches have become essential to SOC design to reduce these adverse effects. However, … Read More


How Not To Be Incoherent

How Not To Be Incoherent
by Bernard Murphy on 01-01-2016 at 7:00 am

The advantage of working with cache memory is the great boost in performance you can get from working with a local high-speed copy of chunks of data from main memory. The downside is that you are messing with a copy; if another processor happens to be working in a similar area, there is a danger you can get out of sync when reading and writing… Read More