clock with nanoseconds

First, background:Recently, a project has been taken over, the core chip is both the LPC17XX series MCU, core arm of the COTEX-M3 core.If you want to play with an MCU, you have to take care of its clock!The clock is to the MCU, like the human heart. It gives the AHB, APB Bus The blood (clock frequency), and the devices that hang on the AHB (Advance High bus) bus

There are four clock sources in 9200: Slow clock (SLK) Main clock) PLLA, pllb There is a difference between the master clock and the host clock. The main clock refers to the clock of t

In stm32, there are five clock sources:HSI,HSE,LSI,LSE,PLL. ①HSIIt is a high-speed internal clock, RC oscillator, and the frequency is 8 MHz. ②HSEIt is a high-speed external clock, which can be connected to a Z/Ceramic Resonator or an external clock source. The frequency range is 4 MHz ~ 16 MHz. ③LSIIt is a low-s

Study on auxiliary clock of AT91RM9200 Platform [Date:] Source: MCU and Embedded System Application Author: baili Ren nun, Lanzhou Jiao Tong University [Font:Large Medium Small] 　 IntroductionIn VxWorlks, the implementation of the timer mechanism is based on the clock. Different Timing mechanisms can be selected based on different requirements, such as taskDelay (), WatchDog, and auxili

1. System interruption and clock cycle 1.1 system interruption Interrupt is a hardware mechanism that notifies the CPU Of an asynchronous event. Once the interrupt is identified by the system, the CPU stores partial (or all) context values, that is, the values of some (or all) registers, and jumps to a special subroutine, it is called the interrupt service subroutine (ISR ). Interrupt Service subprograms are used to process events. After processing i

Jitter is defined as the deviation of the signal from its ideal position. This article focuses on clock Jitter and discusses the following types of clock jitter: adjacent periodic jitter, periodic jitter, time interval error (TIE) jitter, phase noise, and phase jitter.Introduction to Clock JitterClock jitter is the deviation of the

Android Phone small Alarm ClockIn daily life work, there are often important things or schedules, and the alarm clock, as a tool to remind people, becomes an indispensable part of many people's lives.The software includes the functions of alarm settings, alarm clock creation, alarm clock off and other modules. The use of this application is simple, easy to learn

Transferred from: http://blog.csdn.net/droidphone/article/details/7975694Clock source is used to provide a time baseline for the Linux kernel, and if you get the current time with the Linux Date command, the kernel reads the current clock source, transforms and returns the appropriate time units to the user space. At the hardware level, it is usually implemented as a counter driven by a fixed clock frequenc

From the perspective of clock source, there are two types of external clock (E) and internal clock (I ).From the perspective of clock rate, there are two types of high-speed clock (HS) and low-speed clock (LS ).In combination, the

First, in the STM32, there are five clock sources for HSI,HSE,LSI,LSE,PLL. The ①HSI is a high-speed internal clock with an RC oscillator at a frequency of 8MHz. The ②HSE is a high-speed external clock that can be connected to a quartz/ceramic resonator or to an external clock source with a frequency range of 4mhz~16mhz

It is not complete enough to write it casually. Remember it for the moment, and there are still some things you haven't figured out !~ Recently, we are working on porting the new kernel version, and bringing the original BSP to the latest kernel 2.6.31-rc7 (which has been released again ). When rewriting the system timer (sys_timer), I found that there is always something missing, and I don't know anything. The boss's proposal + refer to Daniel'sCodeAnd found that the BSP did not have

, scalability, high efficiency, industry unity, good compatibility, portability strong; Xdc is essentially a TCL language, but it only supports basic TCL syntax such as variables, lists, and operators, and syntax for other complex loops and file I/O can be supplemented by a Tcl file in Vivado. (The reader who is interested in Tcl's topic can refer to another article by the author, "Tcl's application in Vivado") The main differences between XDC and UCF are two points: Xdc can be read a

STM32 clock System for a skilled microcontroller development should be more familiar, but for the novice without too many basic (such as I one months ago), see such a clock system diagram inevitably have a nod big, But when it comes to understanding the designer's purpose and then looking back at a picture like this, you'll find it's not a difficult thing to understand. STM32F103 has 5

Article Title: Linux clock Processing Mechanism. Linux is a technology channel of the IT lab in China. Includes basic categories such as desktop applications, Linux system management, kernel research, embedded systems, and open source. In Linux, many activities are related to time, such as process scheduling and network processing. Therefore, understanding the clock processing mechanism in the Linux operati

How to set alarm time for iphone5 under iOS7 systemAn alarm clock is essential for office workers, but the traditional alarm clock does not set the bell, always listens to a kind of voice to get up, long time can let a person be bored. The use of iphone5 built-in ringtone function, you can set morning exercises music alarm clock, you can also make a piece of pian

1. There are two types of clocks under Linux:1.1 Real Clock RTCThe "Real Time Clock", which is powered by the onboard battery, is also called the RTC or the CMOS clock, the hardware clock. When the operating system shuts down, use this to record the time, but for the running system is not the time.1.2 System

Ⅰ , overviewFor the system clock should know its role, is to drive the whole work of the heart of the chip, if not, it is equal to the person has no heartbeat.For friends using board learning, the knowledge of the RCC system clock is not well configured, because the crystal oscillator provided by the board is basically the official standard clock frequency, using

Clock gate, English name gate clock. The so-called "door-control" refers to the logical output of one clock signal and another non-clock signal. For example, you use a control signal "and" CLK "to control the CLK's effective time.This is used in ASIC to reduce power consumption, because the power consumption is mainly

1. System interruption and clock cycle 1.1 system interruption Interrupt is a hardware mechanism that notifies the cpu Of an asynchronous event. Once the interrupt is identified by the system, the CPU stores partial (or all) context values, that is, the values of some (or all) registers, and jumps to a special subroutine, it is called the interrupt service subroutine (ISR ). Interrupt Service subprograms are used to process events. After processing is

1. Clock domain: MSYS, Dsys, PSYS(1) because the s5pv210 clock system is more complex, the internal peripheral module too many, so the entire internal clock divided into 3 chunks, called 3 domains.(2) MSYS:CPU (Cortex-a8 Core), DRAM controllers (DMC0 and DMC1), Iramirom(3) Dsys: All the modules related to video display, codec, etc.(4) PSYS: And the internal vario