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你好。
我想知道例如while循环需要多少个时钟。 你对这件事有什么想法或文章吗？ 以上来自于谷歌翻译 以下为原文 Hi. I wanted to know that for example how many clocks a while loop takes. Do you have any ideas or any articles on this matter? 
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21个回答
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1.用范围计时，或
2.看看拆卸。 以上来自于谷歌翻译 以下为原文 1. Time it with a scope, or 2. Look at the disassembly. |
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如何使用反汇编来获取时钟数？
每个拆卸线只有一个时钟？ 以上来自于谷歌翻译 以下为原文 How can I use disassembly to get the clock numbers? Each disassembly line is just one clock? |
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您需要查看处理器文档，了解每个不同指令所需的周期数，并将其乘以循环迭代。
如果您想知道不同处理器需要多少个周期，您需要研究设计和功能。 以上来自于谷歌翻译 以下为原文 You'd need to review the processor documentation as to how many cycles each different instruction takes, and multiply that by the loop iterations. If you want to know how many cycles different processors take you'll need to study the design and functionality. |
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您想要解决的根本问题是什么？
我想你不想数周期来计算周期... 以上来自于谷歌翻译 以下为原文 What is the underlying problem you want to solve? I guess you do not want to count the cycle to count the cycles... |
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是的。我有一个四位数的7段，我必须一直刷新它以显示数字。但问题是我使用DS18B20的温度，它需要大约700毫秒来完成转换并给我结果。我只是想知道每次调用display子程序刷新7个段所需的循环次数，并使用display子程序而不是delay子程序。
另一个是我想写自己的延迟子程序，我不知道应该使用多少时间或者fors来获得1 us延迟。 以上来自于谷歌翻译 以下为原文 Yeah.I have a four digit 7 segments that I have to refresh it all the time to show the numbers.But the problem is that I'm using DS18B20 for temperature and it needs about 700 ms to finish conversion and give me the result.I just wanted to know every time I call the display subroutine that refreshes the 7 segments how many cycles it takes and use the display subroutine instead of the delay subroutine. The other is that I want to write my own delay subroutine and I don't know how many whiles or fors should I use for example to get 1 us delay. |
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也许当你的STM32 MCU具有丰富的定时器时，使用定时器可以更容易地可靠地测量微秒。
计数周期可能无法可靠地工作，因为编译器优化代码并且代码大小（以及因此周期数）取决于编译器配置 - 请参阅编译器的Ox设置。 以上来自于谷歌翻译 以下为原文 Probably when you have STM32 MCUs with abundance of timers it would be easier to use timers to measure microseconds reliably. Counting cycles might not be working reliably because the compiler optimizes the code and the code size (and consequently number of cycles) depends of the compiler configuration - see Ox settings for compilers. |
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我正在使用stm8s.Are他们能够通过计时器产生我们的延迟吗？
以上来自于谷歌翻译 以下为原文 I'm using stm8s.Are they able to generate us delays with timers? |
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我没有注意到帖子是在STM8部分打开的。
对不起，我不知道STM8家族。对于8苦，它可能是要走的路。 以上来自于谷歌翻译 以下为原文 I have not noticed that the post was opened in the STM8 section. I am sorry but I do not know the STM8 family. For 8 bitters it might be the way to go. |
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如果您不想计算指令周期，请使用GPIO引脚，在输入时将其驱动为高电平，在您离开时将其驱动为低电平，然后在示波器上触发并测量脉冲宽度。
要在芯片侧进行测量，请使用自由运行的16位TIM，可能为1 MHz，如果溢出则为较慢，并在进入和退出时读取TIM-> CNT，然后计算增量刻度。即delta = finish_tick - start_tick 以上来自于谷歌翻译 以下为原文 If you don't want to count instruction cycles use a GPIO pin, drive it High as you enter, drive it Low as you leave, and then trigger on an oscilloscope and measure the pulse width. To measure on the chip side, have a free running 16-bit TIM, perhaps a 1 MHz, or slower if it overflows, and read TIM->CNT at entry and exit, then compute the delta ticks. ie delta = finish_tick - start_tick |
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如果将TIM设置为1 MHz时钟，则可以通过查看CNT值来观察1us粒度的间隔。你可以按这样的价格打断。
start = TIM-＆gt; CNT; while（（TIM-> CNT-开始）＆lt; 100）; //等100us 以上来自于谷歌翻译 以下为原文 If you set the TIM to clock at 1 MHz you can observe intervals with 1us granularity by looking at the CNT value. You can interrupt at such rates. start = TIM->CNT; while((TIM->CNT - start) < 100); // Wait 100us |
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void delay_us（unsigned int d）
{ TIM2_Cmd（ENABLE）; 而（（（TIM2→CNTRL）|（（TIM2→CNTRL）以下为原文 void delay_us(unsigned int d) { TIM2_Cmd(ENABLE); while( ((TIM2->CNTRL)|((TIM2->CNTRL)<<8))<=d); TIM2_Cmd(DISABLE); TIM2->CNTRL=0; TIM2->CNTRH=0; }void delay_ms(unsigned int d) { while(d){d--;delay_us(1000);} }I've written this code for my delay functions but they do not work. The timer CNT counts each 1 us. |
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通过计时器isr运行你的led更新功能，因此1wire例程不会阻止它。
以上来自于谷歌翻译 以下为原文 Run your led update function through a timer isr so it is not blocked by the 1wire routines. |
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我不是主张重复重置和启用/禁用定时器。我说要让它自由运行并增加当前和起点。
如果处理8位值在STM8上最有效（不使用，也不计划），那么可能将延迟分解为200us或100us，因此代码更紧密，抖动机会减少。 以上来自于谷歌翻译 以下为原文 I'm not advocating the repeated resetting and enabling/disabling the timer. I'm saying to let it free run and delta the current and start points. If dealing with 8-bit values is most effective on the STM8 (not using, don't plan too), then perhaps decompose the delays into 200us or 100us pieces so the code is tighter and the opportunity for jitter reduced. |
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你的意思是这些8位MCU我不能使用定时器获得1 us延迟？
注意：原始帖子包含大量线程对话，只能迁移到第9级 以上来自于谷歌翻译 以下为原文 You mean with these 8-bit MCUs I cant get a 1 us delay using the timer? Note: the original post contained a large number of threaded conversations and was only able to be migrated to the 9th level |
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在嵌入式编程中学习一些课程。
从长远来看，你走的路只会伤害你的学习。 以上来自于谷歌翻译 以下为原文 take some classes in embedded programming. you are going down a path that can only hurt your learning in the long run. |
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如果我有可能会这样做。但这些课程不会免费，作为学生，我负担不起费用。
以上来自于谷歌翻译 以下为原文 If I had the possibility I would do that.But these classes will not be free and as a student, I can't afford the expenses. |
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有些课程是免费的。看看edX和类似的举措：
https://www.edx.org/course/embedded-systems-shape-the-world-microcontroller-inputoutput 书籍也是学习和验证实践知识的好方法。 以上来自于谷歌翻译 以下为原文 There are some classes available for free. Look at edX and similar initiatives: https://www.edx.org/course/embedded-systems-shape-the-world-microcontroller-inputoutput also books are good way of learning and verifying the knowledge in practice. |
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“
我付不起这笔费用。 不幸的是，这是一个艰难的地方。 话虽如此，在解决技能组合之外的问题之前，您可能需要关注基础知识。 现在减速通常会让你以后跑得更快。 以上来自于谷歌翻译 以下为原文 ' I can't afford the expenses.' it is a tough spot to be in, unfortunately. with that said, you may want to focus a little bit on the basics before tackling issues outside of your skill set. slowing down now often allows you to run faster later. |
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