转换DMA UART代码以在PIC32MX170F256B上运行时出现问题

我怀疑问题可能是我没有对齐UART和DMA之间的中断优先级，但是我不清楚如何做到这一点…（它是自动的，不管主处理机中断优先级如何）我认为DMA ISR是可以的，我不真正理解DMA是如何处理UART中断的，而不是DmaChnSetEventControl上的链路。欢迎所有的建议。关于检查手册。再一次。。。



      以下为原文

    I suspect the problem may be that I have not aligned the interrupt priorities between the UART and the DMA, but I am not clear on how to do this... (is it automatic, regardless of main processor interrupt priorities?)
I think that the DMA ISR is OK; I do not really understand how the DMA handles the UART interrupt, other than the link that is made in DmaChnSetEventControl.
All advice welcome.  About to check the manuals.  Again...

另一个问题，恐怕。原始代码不能启用UART中断，即：-OpenUART1（UARTAGEN）UARTZONNOPARY8PAR8，UARTHAR1STOBIT，UARTHARTITIN TXBUFIUN空UTARTIN IN RXYCHAR，PBCK／16 / BaDATRE-1）；/ /选择波特率，8NNI混淆了我；我启用了UFART中断，使用FIFO库函数。以前我已经将代码修改为：OpenUART1（UARTAGEN）UARTZONIOPARY8PARY8UTURS1SCOBIT，UARTHARXRXIN使能UARTHARTXII使能UARTHARTIN TIXBUFIZULL UUARTIN IN RXYCHAR，PBCK／16／BaDATRE-1）；/ /选择波特率，8N-1-这没有区别。问题是UART中断是否需要在UART中设置合适的位之前触发，以触发DMA响应——是这样吗？该示例将建议在任何情况下设置该位，并且中断不需要被具体地启用。



      以下为原文

    Another question, I'm afraid.  The original code did not enable the UART interrupts i.e. it was:-
 OpenUART1(UART_EN|UART_NO_PAR_8BIT|UART_1STOPBIT, UART_INT_TX_BUF_EMPTY|UART_INT_RX_CHAR,
            pbClk/16/BAUDRATE-1);   // selected baud rate, 8-N
This confused me; I enabled the UART interrupts in my code, using the FIFO library function.  I had previously modified the code to:
 OpenUART1(UART_EN|UART_NO_PAR_8BIT|UART_1STOPBIT, UART_RX_ENABLE|UART_TX_ENABLE|UART_INT_TX_BUF_EMPTY|UART_INT_RX_CHAR,
            pbClk/16/BAUDRATE-1);   // selected baud rate, 8-N-1
This made no difference.  The question is whether UART interrupts need to be enabled before the appropriate bit is set in the UART to trigger the DMA response - is this the case?  The example would suggest that this bit is set in any case, and that the interrupts do not need to be specifically enabled.

嗨，我没有尝试过很多，所以不能发现需要什么使它工作。围绕中断启用的术语是不清楚的，中断使能通常意味着当中断标志被外围设置时，中断控制器可以中断CPU。对于UART，有控制位设置。在数据表中引起中断标志的事件，这些被称为“中断模式选择”位，而不是在PLIB设置中的UART启用。当使用DMA时，我认为应该选择这些，以便为发送或接收的每个字节设置中断标志，这意味着：UXSTATITITS.UTXISEL =0；以及：UxStestIt.UrxSele= 0；这与重置默认值相同，因此不需要设置。UART中断不需要启用。中断启用是中断控制器的一个属性，无论在接收或传输字符时CPU是否中断。当DMA被期望处理传输时，这不是你想要发生的。同样地，中断优先级和中断控制器和CPU之间的关系，CPU是否应该被中断，或者当另一个中断已经活动时，CPU是否中断，DMA控制器使用中断。从UART发出的标志信号启动下一个传输。我在任何地方都没有找到一个很好的描述，这个信令实际上是如何运作的，似乎中断标志寄存器不参与其中。迈西尔



      以下为原文

    Hi,
I have not tried much of this, so cannot spot what will be needed to make it work.
 
Terminology around interrupt enable is unclear,
Interrupt enable usually means enabling Interrupt controller to interrupt the CPU when a interrupt flag is Set by a peripheral.
For UART, there are control bits to set what events to cause interrupt Flag to be raised,
in datasheet, these are called 'Interrupt Mode Selection' bits, Not UART Enable as in Plib settings.
When DMA is used, I think these shall be selected such that interrupt Flag is set for every byte transmitted or received, meaning: UxSTAbits.UTXISEL = 0; and: UxSTAbits.URXISEL = 0; 
This is the same as reset default, so shouldn't need setting.
 
UART interrupts should Not need to be enabled.
Interrupt Enable is a property of the Interrupt controller, whether the CPU shall be interrupted when a character have been received or transmitted. This is exactly Not what you want to happen, when DMA is expected to handle the transfer.
Same with Interrupt Priority, that is also a matter between Interrupt Controller and CPU, whether the CPU shall be interrupted, or not, when another interrupt is already active.
 
DMA controller use the Interrupt Flag signal from UART to initiate the next transfer.
I have not found a good description anywhere, of how this signaling actually function,
it seem that Interrupt Flag Register is Not involved in this.
 
   Mysil

亲爱的Mysil，谢谢你的注意。你的评论很有说服力，并与我所做的额外阅读联系在一起。它也与原始代码相吻合，这显然没有启用UART中断。我会检查这是否有任何区别，但我认为我已经尝试过没有UART中断的代码，但没有成功。我必须做一些明显的错误，我只是看不见。最好的祝愿，VJM



      以下为原文

    Dear Mysil,
Thank you for your note.  Your comments make sense, and tie up with the additional reading that I have done.  It also tallies with the original code, which explicitly did not enable the UART interrupts.  I will check to see if this makes any difference, but I think that I have already tried the code without the UART interrupts, and was not successful.  I must be doing something obviously wrong; I just cannot see it.
Best wishes,
VJM

亲爱的Mysil，我已经删除了FIFO中断设置，但没什么区别。代码仍然显示提示（和PBCK的值），并且不对键盘作出响应。更改是注释该行；我认为这足以证明点：//SET FIFO模式//UARTSetFifoMode（UART1，UARTHYBASTTHONTRON ORXXNOTHOPENUTY UARTHYBASECTORION TXXON）；感谢周围的人、发送者和接收者，谢谢你的建议；不幸的是，仍然在挣扎！最美好的祝愿，VJM



      以下为原文

    Dear Mysil,
I have removed the FIFO interrupt setting, but it made no difference.  The code still displays the prompt (and the value of pbClk), and does not respond to the keyboard.
The change was to comment out the line; I think that this is sufficient to prove the point:
    // set FIFO mode
    //UARTSetFifoMode(UART1, UART_INTERRUPT_ON_RX_NOT_EMPTY | UART_INTERRUPT_ON_TX_DONE);
    // enable peripheral, transmitter and receiver
Thanks for the suggestion; still struggling, unfortunately!
Best wishes,
VJM

嗨，我想你首先应该有一个例子，它使用中断，然后移动到DMA。一些例子：http://www. EC.Euu/Lunt/CursSe/ECe47 60/PIC32／PLBIIAppPLES/PLBYEXPLUES/http://SuroSurfGe.NET/PrimeSt/PIC32 UART传输DMA/问候



      以下为原文

    Hi,
I would say you should first have an example which runs using interrupts and then move to DMA.
Some examples : https://people.ece.cornell.edu/land/courses/ece4760/PIC32/PLIB_examples/plib_examples/
https://sourceforge.net/projects/pic32uarttransmissionusingdma/
Regards

嗨，你在运行优化吗？变量：dMnTrand应该被声明为MySysEdv:Actudio：附件是我的版本：UARTHARECHORE示例。已经在PIC32 MX250F128B上使用UART2映射到RB10和RB11上。它与C32 V2.02和XC32 V1.34一起发送38400位/s到一个PIDIT 2 UART工具。再试一次MPLAB X和XC32。迈西尔



      以下为原文

    Hi,
Are you running with optimization?
The variable: DmaIntFlag should be declared volatile
// some local data
volatile int DmaIntFlag; // flag used in interrupts
 
   Mysil
 
Edit: Works for me.
Attached is my version of the: uart_echo  example.
Have tried it on PIC32MX250F128B  using UART2 mapped to RB10 and RB11.
Works with C32 v2.02 and XC32 v1.34  sending 38400 bit/s to a PICkit 2 UART tool.
Project is MPLAB 8.92
Maybe trying MPLAB X and XC32 another day.
 
   Mysil
 
   Attachment(s)

uart_echo.zip (11.14 KB) - downloaded 52 times

亲爱的RISC和MysIL，我对延迟反应的道歉——时区的差异部分归咎于我，我怀疑！我已经中断了在其他领域的工作，一般来说，所以我认为我有一个PIC32的操作这方面的合理把握，但这是一个有趣的一点。我当然会审查您提供的参考资料。是的，我正在运行优化，恐怕我没有想到这个方面，恐怕。我将重新编译，没有优化，以及纠正你指出这个变量作为“易失性”的优秀点。这是一个很好的捕捉！像往常一样，问题假设——在这种情况下，代码是“好”的，并且覆盖了所有的情况。我将运行在我的自定义硬件上提供的代码MysIL，看看我是否能复制他的成功（适当修改以适应我使用的引脚上的UART1）。如您所知，我使用XC32 V1.40（通常是O2），以及最新的MPLAB X。我也已经打算回到真正的基础上，并且在内存传输中尽可能简单地让DMA在内存中运行，以确保我理解这个引擎的运行。我非常感谢您的建议和支持。再次感谢。我将在今天晚些时候报告。祝你好运，VJM



      以下为原文

    Dear RISC and Mysil,
Apologies for the delay in responding - time zone differences partly to blame, I suspect!
I have interrupts working well in other areas, in general, so I think that I have a reasonable grasp of this aspect of the PIC32's operation, but it is an interesting point.  I will certainly review the references you were kind enough to provide.
Yes, I am running with optimisation; I had not thought about this aspect, I'm afraid.  I will re-compile with no optimisations, as well as correcting the excellent point you make about declaring this variable as 'volatile'.  This is a good catch!  As always, question assumptions - in this case that the code was 'fine' and covered all cases.
I will run the code Mysil provided on my custom hardware to see if I can duplicate his success (suitably modified to suit UART1 on the pins I use).  As you know, I use XC32 v1.40 (typically with o2), and the latest MPLAB X.  I also already intended to go back to real basics and get DMA running internally in memory transfers as simply as possible to ensure that I understood the operation of this engine.
I really appreciate your advice and support - many thanks again.  I will report back later today.
Best wishes,
VJM

亲爱的同事，为延迟道歉-我被锁在外面，尽管多次尝试要求密码重置-只是刚刚清除！建议的变化没有区别，而且“好”的代码在我的系统上没有运行在UART1上。然后我更深入地挖掘，并且意识到UART上的“数据接收”位没有按照预期设置，尽管在合适的PIC32引脚上出现了良好的信号。这表明问题是在系统设置中，而不是在DMA UART代码本身中。然后我输入了我的“标准”PIC32×PrimMA指令来设置设备，嘿！我附上下面两个版本的信息。/---------------*/*-Pracm配置，FPLLIdIV= DIVIO2O* PrimaMac配置文件FPLLoDIV= DIVIZ2//是DIVIO1PARMA配置，FPLLMUL= MULL2020，PracMA配置FFDTEN= OF//开机，用于生产一个配置WTTPS＝PS131072//初始设置为4秒；参见Microchip文档，即：TraceMang-COMFIG配置FFSCONEN＝O//需要启用RTC二级振荡器α-PrimaMac配置，ICESL＝ICSYPGX2//在ISS 2板上改变/ /下设置不工作/ ** PrimaMatlab配置FPLLMUL= Mule20，FPLLIdIV= DIVIZ2，FPLLoDIV= DIVIZ2，FWDTEN＝OX-PARMMA配置PASCMOD＝XT，FNOSc= PrPLL，FPBDIV= DIVI2*/CODEI将建议文档在这方面有点有限，并且我使用的PIN（RA4或PIN 12）冲突。我知道有必要清除用于数字输入的引脚的模拟设置（在我的情况下，所有引脚），因此安塞拉已经设置为0。问题的最有可能的原因是SoSO，以及相关联的Apple TracMA指令（FsOsCon＝OFF）来关闭这个问题。当然，这不会影响UART2，它将与原UART的正确操作结合在一起。我可能错了，我很感激证实这一结论。吸取的教训是：1。DMA UART不需要在UART上启用中断——事实上，如果它们是…2，它可能是不稳定的。如果你改变了设备或外围设备的数量，不要假设在任何微芯片的例子中都是合适的。在较小的设备上对引脚进行冲突的功能分配的双重检查；在我的例子中，我相信次级振荡器冲突，这在文档中是不清楚的（请确认！）4。对提供的代码有信心，但检查和检查再次…道歉，如果我陈述众所周知的点，但我相信，共享的经验总是有价值的！再次感谢你们的支持，VJM



      以下为原文

    Dear Colleagues,
Apologies for the delay - I was locked out despite several attempts at requesting a password reset - only just cleared!
The suggested changes made no difference, and the 'good' code did not run on UART1 on my system.
I then dug more deeply, and realised that the 'data received' bit on the UART was not being set as expected, despite good signals appearing on the appropriate PIC32 pin.  This suggested that the problem was in the system setup, rather than in the DMA UART code itself, perhaps.  I then imported my 'standard' PIC32 #pragma directives to set up the device and, hey presto, it worked!  I attach the two versions below for information.
code
/**-------------------------- PIC32 configuration ----------------------------*/
#pragma config FPLLIDIV = DIV_2
#pragma config FPLLODIV = DIV_2                 //was DIV_1
#pragma config FPLLMUL = MUL_20
#pragma config FWDTEN = OFF     //switch on for production
#pragma config WDTPS = PS131072     //set to 4 seconds initially; see microchip documentation
#pragma config FCKSM = CSDCMD
#pragma config FPBDIV = DIV_2
#pragma config OSCIOFNC = OFF
#pragma config POSCMOD = XT
#pragma config IESO = OFF
#pragma config FNOSC = PRIPLL
#pragma config CP = OFF
#pragma config PWP = OFF
#pragma config BWP = OFF
#pragma config FSOSCEN = OFF    //need to enable for RTC secondary oscillator
#pragma config ICESEL = ICS_PGx2        //changed on Iss 2 board
//the settings below did NOT work
/*#pragma config FPLLMUL = MUL_20, FPLLIDIV = DIV_2, FPLLODIV = DIV_2, FWDTEN = OFF
#pragma config POSCMOD = XT, FNOSC = PRIPLL, FPBDIV = DIV_2 */
code
I would suggest that the documentation is a little limited in this area and that the pin (RA4, or pin 12 on the package that I am using) was conflicted.  I am aware of the need to clear the analogue settings for pins that are used as digital inputs (all pins, in my case), so ANSELA was set to 0 already.  The most likely cause of the problem is SOSCO, and the associated #pragma directive (FSOSCEN = OFF) to switch this off.  This would, of course, not affect UART2, which would tie in with the correct operation on this UART with the original #pragma directives.  I may be wrong, and I would be grateful for confirmation of this deduction.
Lessons learnt:
1. DMA UART does NOT need interrupts on the UART to be enabled - in fact, it can be erratic if they are...
2. Make no assumptions that the #pragma directives are appropriate in any microchip example if you change device or peripheral number; if in doubt, use proven ones that have been derived separately
3. Double check for conflicting function allocation on pins in smaller devices; in my case I believe that the secondary oscillator conflicted, which is not clear in the documentation (please confirm!)
4. Have confidence in code that is supplied, but check and check again...
Apologies if I am stating well known points, but I believe that shared experience is always valuable!
Thanks again for your support,
VJM