[问答]

使用PIC18F47 K40I/MV的EUSAT奇异问题

1796 MPLAB

问答对人有帮助，内容完整，我也想知道答案 0 Heloi最近遇到了一个奇怪的问题，我有一个通过EASART发送字符串的自定义函数，函数如下：ValeSerialWrrad（const char x）{（x）{easART1x编写（x++）；}其中，EasART1x写是MPLAB的默认函数。问题是我能够。使用此功能在PIC18F47 K40浸印足迹，但不UQFN40足迹。（顺便说一下，我上传了完全相同的程序，在两个脚印，DIP工作，但不是另一个）我试图做SerialWrand（“Hello”）；在我的主程序，在我的笔记本电脑串口上看不到任何东西。然而，我发现我只能从UQFN40足迹中发送单个字符，例如EUARTAR1X写（'H'）；我还用示波器检查了TX线，当我使用UQFN40足迹的函数SyralWrad时，看不到任何下拉，但是看到了单字符信号。EUARTAR1X写的好。UART连接对于我的PCB上的DIP足迹芯片和UQFN40芯片来说是简单和相同的：PIC18F47 K40TX-& GT；MCP2221 RXPIC18F47 K40RX——& McP2221 TXONE概念，问题可能是什么？以上来自于百度翻译以下为原文 Hello I have recently encountered a weird problem, I have a self-defined function for sending string through EUSART, function as follow: void serialWrite(const char x) { while(x) { EUSART1_Write(x++); } } Where EUSART1_Write is the default function from mplab. The problem is that I was able to use this function in PIC18F47k40 DIP footprint but not UQFN40 footprint. (By the way, I uploaded the exact same program in both footprint, DIP worked but not the other) Where I tried to do serialWrite("Hello"); in my main program and could not see anything on my laptop serial port. However I found out that I was only able to send out single character from the UQFN40 footprint, e.g. EUSART1_Write('H');. I have also checked the TX line with oscilloscope, I could not see any pull down when I use the function serialWrite with UQFN40 footprint, but saw single character signal with EUSART1_Write alright. The UART connection is simple and identical for the DIP footprint chip and UQFN40 chip on my PCB: PIC18F47k40 Tx --> MCP2221 RX PIC18F47k40 Rx --> MCP2221 TX Any idea what the problem could be? 0
2018-8-28 15:11:34　　评论淘帖0 邀请回答您可以邀请以下用户，快速回答问题 × qun333 该类别下有 57 个回答。邀请回答 caoguiqun 该类别下有 56 个回答。邀请回答技术发广告该类别下有 56 个回答。邀请回答 psw30 该类别下有 44 个回答。邀请回答伊丹姿子该类别下有 41 个回答。邀请回答 uwufwjrw 该类别下有 39 个回答。邀请回答 hetao1111 该类别下有 38 个回答。邀请回答 lc123617 该类别下有 35 个回答。邀请回答欧阳大大该类别下有 32 个回答。邀请回答作死不止该类别下有 31 个回答。邀请回答 asd010 该类别下有 31 个回答。邀请回答 60user92 该类别下有 29 个回答。邀请回答 wy8719 该类别下有 29 个回答。邀请回答嘻嘻爱哈哈该类别下有 28 个回答。邀请回答 haikitty 该类别下有 28 个回答。邀请回答 ju978779 该类别下有 28 个回答。邀请回答 xiuzhen122 该类别下有 27 个回答。邀请回答 pol666 该类别下有 27 个回答。邀请回答 ueywyrsdfs 该类别下有 26 个回答。邀请回答 lhly23 该类别下有 25 个回答。邀请回答举报王伊相关推荐 • PIC18F47K40自行复位 1447 • 如何使用PIC18F47 K40打印无符号长长值PIC 1202 • 是否有一个PIC18F47 K40 EVE板的示意图？ 2310 • PIC18F47K40可以使用3.3V从机的接口吗？ 1127 • 如何用PIC18F47 J53-I/ML计算成品板的带宽？ 1194 • pic18f47k42.h错误？ 3420 • PIC18F47K40的阵列初始化问题 1213 • PIC18F47K40也无法将所有IO用作通用IO 1466 • Usart PIC18f47k40数组3456不显示 1129 • MPLAB Xpress IDE无法识别MPLAB Xpress PIC18F47K40评估板（DM182027） 1440 1个回答

答案对人有帮助，有参考价值 0 我猜想，不工作的芯片是Rev A2，而工作的芯片是一个后来的Rev Rev A2芯片需要臭名昭著的“NVMRG解决方案”（见脚注）。K40的勘误表文档给出了描述和一种方法来处理它，但是最简单的方法是在Pro上输入+NVMReg。注入-GT；XC8连接器-GT；附加选项-GT；勘误线。（对此，您不必将小汇编语言文件添加到您的项目中！）（请参阅附件）注意，这是一个链接器选项，而不是编译器选项。底线：这为应用程序的启动代码添加了两条指令。这是不需要以后的修订，但也不会伤害任何东西。问候，DaveFootnote：即使是谁看过这个错误的勘误，有时认为他们不需要解决办法，因为他们没有明确地使用TBRRD。但是（这是一个很大的但是）访问闪存数据的任何东西都需要这个。真正地。编译器使用TBLRD遍地。以上来自于百度翻译以下为原文 I'm guessing that the chip that does not work is Rev A2 and the chip that works is a later Rev. Rev A2 chips require the infamous "NVMREG workaround" (See Footnote.) The Errata document for the 'K40 gives a description and one way to work around it, but the simplest way is to enter +NVMREG on the Project->XC8 Linker->Additional Options->Errata line. (With this, you do NOT have to add the little assembly language file to your project!) (See Attachment.) Note that this is a Linker option, not a Compiler option. Bottom line: This adds two instructions to the startup code for the application program. It is not required for later revisions, but doesn't hurt anything either. Regards, Dave Footnote: Even people who have read the Errata about this bug sometimes think they don't need the workaround since they aren't explicitly using TBLRD. But (and this is a Big But) anything that accesses Flash data memory needs this. Really. The compiler uses TBLRD all over the place. Attached Image(s)

2018-8-28 15:21:32 评论举报郑雅颖