Word Power Made Easy – Studying Note 001 PART ONE: GETTING OFF TO A GOOD START 1. HOW TO TEST YOUR PRESENT VOCABULARY A TEST OF VOCABULARY RANGE Here are sixty brief phrases, each containing one italicized word; it is up to you to check the closest definition of each such word. To keep your […]
Study Note About CDC Issue
Before we start it, I must declare that most contents that I summarized in this article can be derived from this online paper: Clock Domain Crossing (CDC) Design & Verification Techniques Using SystemVerilog. If you want to dig into some details that I mentioned in this article, you can read that paper as reference. CDC is […]
One-hot State Machine
When I was checking the source code of ARM7-TDMI, a very unusual state machine caught my attention. It was used in the codes of the ALU’s multipliers. After doing some researches, I finally figured out that it was the so-called ‘One-hot State Machine’. I have heard about this kind of state machine when I was […]
How To Build SystemC Compile Environment
I started learning SystemC yesterday, for I found that it is too difficult to understand ArchC if I don’t study SystemC first. Thankfully I still remember all fundamental grammars of C++, so I could just focus on the different ways of hardware description between SystemC and Verilog. The book I am reading is SystemC片上系统设计-陈曦,徐宁仪. If […]
Open Source ESL Design
作者：Kellen Wang 从今天开始我的职能正式改变了，以前一直专注于RTL实现，现在要转变为更高层次的设计级别——ESL，Electronic System Level。所以只会用verilog恐怕是不行了。在网上搜索了一圈，发现目前中文技术世界里还很少有涉及ESL方面的书，虽然这玩意也出来十几年了，唯一的一本书涉及得也不深。据说ESL从出来的那一天起就一直是雷声大雨点小，各种巨头都纷纷认为它是未来的技术方向，同时都暂时不考虑对它的应用进行深入探索。虽然某些公司已经声称发布了基于ESL方法设计的芯片，但目前还只能说停留在实验室阶段。但是没办法，我是一个不能接受“经验”的人，凡事都应当讲究“方法学”，中文搜索怕是不灵了，只能向外国和尚求经。今天在bing.com搜到了一本好书，比较适合用来研究ESL，发现目前还没有中文译本，决定从今天开始看，在这里对重要内容做一些笔记。好了废话不多说，开始吧。 +20
Computer System Architecture Study Note
作者：Kellen Wang 1. 架构与功耗 在电压给定、工作量给定的情况下，降低计算机频率或许可以降低芯片的表面温度，但完成工作量所花费的实际功耗并不会因此降低。如果真的想降低系统功耗的话，必须在降低工作频率的同时降低系统电压。由于功耗与电压是平方关系，只要电压下降一半，功耗就会下降为之前的四分之一，再乘上频率的同比例降低，整个系统的实际功耗会下降为之前的八分之一。因此20年来系统内核电压一直在不断下降，从5V一直降到现在的1V。 随着制程的不断上升，芯片面积越来越小，散热问题越来越严峻。在解决散热问题之前，时钟频率似乎已经到达了一个瓶颈。因此，从2003年以后系统主频就鲜有上升，一直维持在最高3.3Ghz左右。 +30