ptp clock

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

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

, 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

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

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

In the previous section of the discussion, we have been based on the assumption that the clock events in Linux are provided by a cycle clock, regardless of whether the clock_event_device in the system is working in a cycle-triggered mode or in a single-trigger mode, regardless of whether the timer system is operating in a low-resolution mode, or high-precision mode, the kernel does its best to provide cycle

Clock part(1) clock domains5pv210 there are altogether three clock domains: Msys,dsys,psysMSYS: (main system) master clock domain, including cpu,ddr memory, Irom and Iram, etc.Dsys: (display system) shows the clock domain, which is generally related to video in this

First to show you the effect map, interested friends can download the source Oh. Effect Demo Source Download Digital clocks can be applied to some Web countdown effects, Web alarm effects, and web-based apps based on HTML5, and this article will show you how to use CSS3 and HTML to make a very nice digital clock effect without any pictures. Html We first prepare a clock area #

High speed ADC Clock jitter solution The clock jitter of the high-speed ADC affects the SNR of the high-speed ADC, while the signal-to-noise ratio determines the effective range of the analog front-end input. Therefore, it is necessary to determine the effective input range of the analog front end, then determine the SNR that should be satisfied, and then deduce the cl