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32位PWM分辨率！！！！从2MHz的时钟？每周期超过35分钟。哇，好奇的应用程序。



      以下为原文

    32 bit PWM resolution !!!!
From a 2MHz clock?
More than 35 minutes per cycle.
Wow, curious application.
 

我很想知道什么是32位PWM分辨率实际上是有用的。



      以下为原文

    I'm dying to find out what 32 bit PWM resolution is actually useful for.
 

我想象另一种方式。PWM在2MHz的频率和0.5飞秒分辨率的占空比。也许你的解释是正确的。无论如何，32位分辨率不会是真实的，除非时钟抖动小于0.0002 ppm。除此之外，没有8个专用中断引脚的PICS，但是在每个引脚上都有很多CN中断的图片，这对你来说可能是一样的。大多数PICS（给定足够的引脚）将具有所有所需的质量。所以，你需要告诉其他什么是重要的-成本，大小，电源，CPU SPEEDETC。



      以下为原文

   


I imagined it the other way around. PWM at 2MHz frequency and 0.5 femtosecond resolution for the duty cycle. Probably your interpretation is correct.
 
At any rate, 32-bit resolution will not be real unless clock jitter is less than 0.0002 ppm.
 
Other than that, there are no PICs with 8 dedicated interrupt pins, but there are plenty of PICs with CN interrupts on every pin, which is likely to be the same for you.
 
Most PICs (given enough pins) will have all the required qualities. So, you need to tell what else is important - cost, size, power, CPU speed etc.

引脚数限制你到PIC32 MX 100到400系列零件。100和200系列零件是50兆欧零件。300/400系列器件为100兆赫器件，全部支持I2C和串口，部分支持USB，可作为现场编程的较好选择。您可以使用50 MHz的高频晶体，如果您希望使用12或24 MHz晶体（USB所需），并且内部PLL将仍然给您一个50或100 MHz的内部时钟速率。8个中断是可能的，使用5个标准外部中断，一个变更通知。中断，一个计数器和PMP读取输入以产生第八个外部中断。由于这些单元具有5个定时器，对于外部PWM发生器来说，四个2兆赫的PWM时钟是可能的。它们具有5个OC引脚，这是创建PWM脉冲的方式。这是通过设置一个定时器到频率，而OCR引脚是一个集合，当计数器为零时，当计数器达到特定计数时，它被清除。因此，如果定时器在50 MHz时钟，2兆欧输出是通过将时钟除以25，PWM输出可以从1到24时钟宽。虽然所有的OCR输出都使用时钟源的定时器2，但基本PWM频率必须相同，只有所有的OCR输出变化。如果移动到64针芯片，PIC32 MZ，则有9个计数器，OCR输出可以单独计时。它也运行在250兆赫，所以你的2兆赫现在是125个时钟提供更好的解决方案的PWM和处理器甚至可以抖动结束计数在每2MHz时钟周期。DSP PIC（16位处理器）也可以是一个适合，因为它有更多的定时器。



      以下为原文

    The pin counts limit you to PIC32MX 100  through 400 series parts.
 
the 100 and 200 series parts are 50 meg parts.
 
the 300 / 400 series parts are 100 megahertz devices.
 
All support I2C and serial port and some support USB which may be a better choice for field programming. You can use a high frequency crystal at 50 Mhz if you wish though using a 12 or 24 Mhz crystal ( required for USB) and the internal PLLs will still give you an internal clock rate of 50 or 100 mHz respectively.
 
The 8 interrupts is possible using the 5 standard external interrupts, one change notification interrupt, one counter  and the PMP read input to create the 8th external interrupt. 
 
As these units have 5 timers, four pwm clocks of 2 megahertz is possible for an external PWM generator. 
 
They have 5 OC pins which are the way to create PWM pulses. This is done by setting a timer to the frequency and the ocr pin is a set when the counter is zero and it is a cleared when the counter attains a specific count.   So if the timer is clocked at 50 mhz, 2 meg output is creating by dividing the clock by 25 and the pwm output can be from 1 to 24 clocks wide. The base PWM frequency though must be the same with only the pulse width varying as all OCr outputs use timer 2 for the clock source. 
 
If you move up to a 64 pin chip, the PIC32MZ, has 9 counters and the ocr outputs can be separately clocked.   It also runs at 250 mHz so your 2 mHz is now 125 clocks providing better resolution on the PWM and the processor can even dither the end count on every 2mhz clock cycle. 
 
The Dsp pic ( 16 bit processor) may also be a fit as it has more timers.
 

还有PIC32毫米。还有一堆PIC16／18/24和DSPIC33 PICS，它们更适合，但这是PIC32论坛。



      以下为原文

   


Also PIC32MM.
 
There are also bunch of PIC16/18/24 and dsPIC33 PICs which would fit better, but this is PIC32 forum.

希望看起来是任意的。时钟源：外部晶体支持，时钟应该高于40MHz。- 10兆赫与4倍的PLL将不好？每个中断的专用中断请求为何？Flash：32 KB到128KB的Flash需要由架构确定的ID。除非它主要是表。有趣的是，PWM可以在软件中按照给定的规格来完成。



      以下为原文

    The wants look arbitrary.
 
 Clock source : external crystal support, clock should be higher than 40MHz.
-10 Mhz with a 4X PLL would not be good?
Dedicated interrupt request for each interrupt 
-Why?
 Flash : 32kB to 128kB
-The flash need id determined by the Architecture. unless it is mostly tables.
 
It is funny the PWM could be done in software at the specs given.

嗨，对于原来的海报，所有PIC32微控制器，都有PLL倍频器产生高频时钟信号。因此，一个8兆赫，12兆赫，16兆赫，20兆赫或24兆赫晶体，或一个外部晶体振荡器，可以用来创造最高频率的芯片能够处理根据S。如果使用USB，12或24 MHz基频可能是最实用的。也有内部振荡器，如果不需要精确定时或计时，则可以使用。对于开发，您可以选择您想要的家庭中具有最大内存的设备，然后，如果准备的话。一个大规模生产的设计，可以选择一个符合实际需求的设备。实际的内存需求可能很大程度上取决于开发什么工具或积木。UART在所有PIC设备中都是可用的，但在开发过程中不用于编程。它可能对DUM有用。Ping诊断消息，虽然一些家庭在28引脚PDIP封装中有设备可以用于开发，具有更多引脚的设备大多需要开发板。如果您想在该领域更新固件，可以使用任何通信硬件，原则上可以使用。但是这需要引导程序（固件更新程序）与原始程序安装一起准备和安装。



      以下为原文

    Hi,
To the original poster,
All PIC32 microcontrollers, have PLL frequency multipliers to create high frequency clock signals.
Thus a 8 MHz, 12 MHz, 16 MHz, 20 MHz or 24 MHz crystal, or an external crystal oscillator,
may be used to create the highest frequency the chip is able to handle according to specifications.
 
If USB is going to be used, 12 or 24 MHz base frequency may be most practical.
There also are internal oscillators, that may be used if precision timing or timekeeping is not needed.
 
For development, you may select the device with largest memory in the family you want,
then, if preparing a design for mass production, may select a device witch match actual requirements.
Actual memory requirement may depend a lot upon what tools or building blocks are used for development.
 
UART is available in all PIC devices, but is not used for programming during development.
It may be useful for dumping diagnostic messages, though.
Some families have devices in 28 pin PDIP package that may be breadboarded for development.
Devices with more pins, mostly need a development board.
 
If you want to be able to update firmware in the field, any communication hardware available, may in principle be used, but this require a bootloader (firmware update program) to be prepared and installed together with the original program installation.
 
Regards,
   Mysil

如果你确切地解释你想做什么，而不是你认为你应该怎么做，你可能会得到更多有用的帮助。例如，告诉我们你想要产生什么样的PWMs（“100 kHz，占空比为10 ns”），而不是你认为需要多少分辨率。



      以下为原文

    If you explain exactly what you're trying to do, instead of how you think you should do it, you will probably get much more useful help.  E.g., tell us what kind of PWMs you're trying to generate ("100 kHz with 10 ns steps in duty cycle"), not how many bits of resolution you think you need.

同意。要求1和5表明OP真的不知道他在问什么。



      以下为原文

    Agreed.
Requirements 1 and 5 indicate the OP really doesn't know what he is asking about.
 

是的



      以下为原文

    Yes