之前去地平线面试的时候被问到了multicycle path的一点问题,其实这个问题我应该知道,看过<Constraining Designs for Synthesis and Timing Analysis A Practical Guide to Synopsys Design Constraints (SDC)>,但当时回答的不好. 0. 多周期路径 一般情况下数据在任意时钟沿发射,在下一个时钟沿被捕获,但是有时设计者需要延迟几个时钟周期data才被捕获,这就是多周期路径. 默认的建
RTC 原创,转载请写明出处. 一直以来想写一篇关于RTC的总结,可是人太懒,在读完John Z. Sonmez大伽的<软技能代码之外的生存技能>后,终于下定决心,完成这项早已计划中的任务.首先声明,本文是以PC为例来阐述RTC工作的基本原理. RTC的基本概念 RTC(Real Time Clock),实时时钟,是存在于PC(x86)及类PC架构的电路中,其主要的作用是记录设备关机时的时间及在设备开机时提供时间基准,也就是说在设备机器关电的时候,记录下当时的时间,在设备启动时为设备内部的时间
Timing delays in a double data rate (DDR) dynamic random access memory (DRAM) controller (114, 116) are trained. A left edge of passing receive enable delay values is determined (530). A final value of a receive data strobe delay value and a final va
http://www.howtogeek.com/177790/why-you-cant-use-cpu-clock-speed-to-compare-computer-performance/ Why You Can't Use CPU Clock Speed to Compare Computer Performance Shopping for a new computer? Don't pay too much attention to CPU clock speed. "CPU spe
今天介绍一下clock这个函数的使用,它是C标准库的一部分,声明在头文件<time.h>中,返回处理器使用的时间值,函数声明为: clock_t clock(void); 这个函数看起来很简单,但是当使用时还是有不少需要注意的地方,让我们先看看clock_t这个类型,它表示程序所占用的处理器时间,具体的实现可以是整形或者浮点型,例如我们如果查看codeblock12.11中的time.h文件,可以看到如下定义: /* * A type for measuring processor time
用两个256x16的基本存储器构成512x16的数据存储器,因为256x16的基本存储器读写时序不太符合MCU的要求,于是改写之.利用下降沿控制输入,作为基本存储器控制时钟,而上升沿控制数据输出寄存器,满足读写时序要求.借鉴学习ASIC中同时有上升沿和下降沿的设计注意事项. Avoid mixed clock edges = Avoid using both positive-edge and negative-edge triggered flip-flops. 1) If must use
"Delta cycles are an HDL concept used to order events that occur in zero physical time."sigasi.com Taking the definition for Sigasi, what VHDL calls delay cycles, Verilog calls a scheduler. How VHDL and Verilog determine the order of zero time e
How do we measure a CPU's work? Whether it's fast or not depends on three factors: IPC, Hz, Clock speed. IPC means instructions per cycle, Hertz[Hz] means cycles per second and Clock speed's definition is always the large number of Hz. So if two CPUs
The multi Interfacemulti接口 The easy interface as described in detail in this document is a synchronous interface that transfers one file at a time and doesn't return until it is done.easy接口是同步的,调用同步接口传输文件,需要等到传输完毕函数才会返回. The multi interface, on the o
在使用JSONObject.fromObject的时候,出现“There is a cycle in the hierarchy”异常. 意思是出现了死循环,也就是Model之间有循环包含关系: 解决办法: 使用setCycleDetectionStrategy防止自包含 代码: JsonConfig jsonConfig=new JsonConfig(); jsonConfig.setIgnoreDefaultExcludes(false); jsonConfig.se
