in cotex-m3:The Systick timer is bundled in the Nvic to generate a Systick exception (exception number: 15). In the past, most operating systems needed a hardware timer to generate tick breaks required by the operating system as the base-times for the entire system. For example, for multiple tasks to allow a different number of time slices, to ensure that no one task can occupy the system, or a certain time range of each timer cycle to specific tasks, as well as the operating system provides a
To view the system clock with the oscilloscope, the system clock is output to the MCO pin.After one night, I saw the waveform.First, create an empty project. Code Comment out:; Import systeminit; Delete systeminit write RCC initialization function by yourself; LDR r0, = systeminit; Blx R0The following is a setup function that uses HSI as the system clock. If the
Reprinted: http://www.kongch.com/2011/08/vector-clock-understanding/
Vector clock is an algorithm used by Amazon's dynamo to capture the causal relationship between objects of different versions. According to dyanmo paper, the vector clock is actually a (node, counter) pair list (that is, a (node, counter) List ). The vector
JavaScript html5 canvas draws the clock effect (2), html5canvas
For H5, canvas is one of its most distinctive features. With it, we can draw various images on the web page and make some games. The usage of the canvas label is also described in many tutorials on the Internet. Today we will use canvas for a small clock. Complete code can be found at https://github.com/wwervin72/html5-
clock_t clock (void);Calculates the processor time used by the calling processHead file is Return ValueClock returns the number of clock ticks of elapsed processor time. The returned valueis the product of the amount of has elapsed since the start of a process andThe value of the CLOCKS_PER_SEC constant. If The amount of elapsed isUnavailable, the function returns–1, cast as a clock_t.RemarksThe
Tips:
1. Mobile network to ensure a good state, if due to network status difficult to calculate your exact location, then no matter where you are, the alarm clock will ring when the time arrives.
2. The position alarm range is about 1 kilometers, the mobile phone is positioned within 1 kilometers, the alarm clock will ring.
For example: When you are in the company, you need a daily alarm
Understanding the STM32 clock is the basis for our application timers and more, based on recent work:Here is the clock tree for STM32:1. First note is the picture of the green Circle of two, HSE and HSI respectively represents the external clock and internal clock, where HSE is a high-speed external
In the official Application note, we can see that the PCNT oversampling routine uses a 32 Khz clock source as the reference clock source. There is also an orthogonal code. Although the external signal is used as the clock of the PCNT module, we rarely use orthogonal code.
In addition, we can better master this function only when we have used it. Therefore, we sti
Instructor song,Hua Qing vision embedded college lecturer.
1.1 Introduction to rtc
In an embedded system, RTC is usually used to provide reliable system time, including hour, minute, second, and year, month, and day, it is also required that the system work properly when it is shut down (usually powered by a backup battery ). Its Peripheral does not require too much auxiliary electrical channels. Typically, it only requires a high-precision 32.768khz crystal and resistance capacitor, as shown in
parts of the the system Power and Thermalmanagement controllers), which makes it difficult to createplatform-independent solutions.
The "problem" a common clock framework faces is the sheer numberof different struct CLK definitions scattered Oughout the Armtree. There are more than two dozen definitions in arch/armcurrently, but the proposal to a commonframework not surprisingly re Duces that number to one. Implementations canwrap the struct CLK in
Transferred from: http://blog.chinaunix.net/uid-27105712-id-5612512.htmlFirst, the use of the backgroundLet's start with a scene that requires a vector clock . When we write data, we often want the data not to be stored at a single point. such as DB1,DB2 can provide write service at the same time, and all have the full amount of data. The client does not have to worry about data-scrambling, regardless of which DB is written. But in real-world scenario
Example:http://blog.csdn.net/kvw3000This article collects and collates, thanks each section code provider!
Finishing: Go home and Chant (Wang Jitai)
1. Announcements and Counters2. Weather forecast3. The firefly following the mouse4. Status bar text5. Follow the mouse text6. Automatically displays a different maxim at the top subtitle position each time it is opened7. Flash exquisite clock (add)
The appropriate functionality can be achieved by addi
Human clocks hone Hone clock
absrtact: This article introduces an interesting flash clock designed by Japanese: human clock hone hone. Installation is simple, direct JS import, including two styles: transparent background and white background.
Added a funny human clock to the blog hone Hone
STM32 A total of five clock sources, namely:
HSI is a high-speed internal clock, rc oscillator, the frequency of 8MHz;
HSE is a high-speed external clock with a frequency range of 4~6mhz; (can connect quartz/ceramic resonator or external clock source)
LSI is low speed internal
1. How does one implement the system clock interrupt driver rt-thread when the thread time slice is exhausted or the thread is awakened and scheduled after sleep for a period of time? Who is driving this process? The answer is the clock interruption source. Let's take a look at the clock interruption routine: In bsp/stm32f20x/drivers/board. the c source file cont
This article describes how to implement a small clock program.
The Figure 2 shows the execution result of the program example. in the form Load event processing routine, the radius and coordinates of the drawn clock are calculated. when the user adjusts the window size of the clock, the form automatically redraws the content of the
1 6410 Clock SystemFrom the schematic you can know the following:1. Using 12M crystal Oscillator2 has three dividers APLL MPLL EPLL3. Generated four clocks aclk hclk PCLK SCLKHere are the range of applications for several clocks:Which aclk for the system clock, HCLK and PCLK for various peripherals and internal clocks, SCLK for the time being not considered2: initialization ProcessAs can be seen, the SYSCLK
Introduction to Vector clock algorithms. Vector clock algorithm overview 1. Background: first, let's talk about scenarios where Vector clock is needed. When writing data, we often hope that the data will not be stored at a single point. Introduction to Vector clock algorithms for db1 and db2
I. Background
Let's talk a
Author:Liu Hongtao, senior lecturer of Huaqing vision embedded College, and an arm ATC authorized training instructor.
Recently, I plan to develop a PXA270 system for our far-sighted teaching in Huaqing. I will record some of my software and hardware development processes and share and discuss them with you. Have good suggestions everyone must communicate in time, lht@farsight.com.cn. In the previous article, I wrote "PXA270 embedded system design 1: Power Supply Management". Today, I want to wr
Many hardware functions require bus clock support, such as LCD and I2C. This article analyzes the bus clock of S3C2440 and the operations related to the clock frequency of S3C2440 bus in Linux. First, analyze the bus clock of the hardware S3C2440.
1. S3C2440 fclk hclk pclk:
The clo
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