We saw earlier how to use the MMU in your x86 processor (or almost any other modern processor) to space-shift your system’s memory. You can make memory appear to move around in the address space, you can make it magically appear where there isn’t any memory, and you can make it look like you’ve got more memory than you actually do, even making a tiny block of RAM look like a … Read More → "How To Implement Virtual Memory, Part 3"
Many of today’s electronic systems feature multiple printed circuit boards (PCBs) and/or modules. (For the remainder of this column, unless such interpretation is inconsistent with the context, we will assume the term “board” to embrace the term “module.”) Not surprisingly, the system’s designers often wish to pass data back and forth from board to board.
Oftentimes, these inter-board signals involve relatively low-speed data transfer via general-purpose input/output (GPIO) pins or low-bandwidth serial interfaces like I2C (inter-integrated circuit) and I2S (integrated inter-IC sound bus).</ … Read More → "SWA Stands for Stupendous, Wizard, and Awesome"
Earlier this week we looked at one of the most useful ways to leverage virtual memory. But there are other reasons for cracking open your chip’s MMU to see what secrets it holds. One is demand paging and the other page-level protection. Both features are built in to every x86 processor, as well as most other CPUs like ARM and RISC-V.
Best of all, these virtual memory techniques aren’ … Read More → "How To Implement Virtual Memory, Part 2"
Doug had cinnamon apple oatmeal for breakfast the day he hit the championship-winning home run.
For the big game, the team was wearing their preferred dark uniforms rather than the “away game” white ones. The game was in their home stadium. The wind was out of the southwest at about ten knots, making a nice breeze from behind home plate toward the left field fence. The team’s biggest fan, sitting in section D, row 3, seat 7, was wearing his lucky Def Leppard T-shirt, had his Snap-On Tools ball cap on … Read More → "Can Intel Succeed?"
As if it weren’t already complex enough, x86 processors from Intel and AMD allow you to make software and memory even more indirect and complicated. This week we dive into virtual memory, demand paging, and other advanced features that x86, ARM, RISC-V, and most other modern CPUs all implement but that aren’t well understood.
What the heck is virtual memory? It can mean a couple of different things, but usually it means you’re pretending that your system has more memory than it actually does. You’re faking … Read More → "How To Implement Virtual Memory on x86 Chips"
One of the all time great English rock bands was The Police. Emerging in the British new wave scene playing a style of rock influenced by punk, reggae, and jazz, they became globally popular in the late 1970s and early 1980s.
In 1979, I saw them playing live at the Queen’s Hall in Leeds, England, and I was amazed by how the three of them — Sting (primary songwriter, … Read More → "Don’t Stand So Close to Me!"
It may seem counterintuitive, but 2020 was a very good year. Good if you were in the business of making and selling semiconductors, that is. After a depressing 2019, 2020 saw global sales of processors, memories, and miscellaneous chips of every description rise by a healthy 7.3%. That’s good news!
These numbers … Read More → "2020 Was a Great Year! (for Chips)"
When you’re in the processor business, you’re also in the compiler business. Like it or not, inventing a new CPU or MCU with its own instruction set means you’re also on the hook for its entire software-development toolchain. In fact, a lot of “chip companies” employ more programmers than circuit designers.
And you thought inventing a new computer was hard.
That was the tall order facing Eta Compute. One of many, in fact. The small startup took on all sorts of … Read More → "Eta Compute Pivots to AI Software"
When I was a little lad about six years old growing up in England circa 1963, my mom and dad were both working, so I used to spend the halcyon days of summer up the road at my Auntie Barbara’s house hanging out with my cousin Gillian (who was one year younger than me) and the other kids on the street.
You have to remember that our homes were small by American standards (“three-up, three-down, semi-detached,” which they call a duplex in the USA), with correspondingly sized furniture and appliances. … Read More → "Say what? When it Comes to Voice Control, The Future is Now!"
With all the turmoil in the world, it’s nice to know that we can rely on our connected cloud-based devices. Oh, wait. No, we can’t. They’re about as reliable as fifth-hand ’50s Fiat.
Cloud behemoth Google went down last month, stranding thousands upon thousands of users around the globe who rely on Gmail, Google Docs, YouTube, Hangouts, Analytics, Google Maps, Blogger, and nearly everything else Google owns (which is to say, nearly everything). It was like losing electricity or running water if you were a G-Suite (sorry, … Read More → "Say Goodbye to More Cloud Services"
