TM4C129X UART 中断问题

你好，

我测试C:\ti\TivaWare_C_Series-2.1.0.12573\examples\boards\ek-tm4c1294xl\uart_echo下的例子，使用串口调试助手可以正常收发，但是将中断作如下修改后无法再次进入中断，另外发现只有调用发送相关的函数才能再次进入中断，请问如果我只在中断中接受数据应该怎么样做？谢谢

uint8_t temp = 0;
void
UARTIntHandler(void)
{
uint32_t ui32Status;

//
// Get the interrrupt status.
//
ui32Status = ROM_UARTIntStatus(UART0_BASE, true);

//
// Clear the asserted interrupts.
//
ROM_UARTIntClear(UART0_BASE, ui32Status);

//
// Loop while there are characters in the receive FIFO.
//
while(ROM_UARTCharsAvail(UART0_BASE))
{
//
// Read the next character from the UART and write it back to the UART.
//
// ROM_UARTCharPutNonBlocking(UART0_BASE,
// UARTCharGetNonBlocking(UART0_BASE));
temp = UARTCharGetNonBlocking(UART0_BASE);//将接收到的数据放入一个变量
}
}

xyz549040622：

你是不是没有清接收缓冲区呢，很简单，你读一下接收中断标志，接收缓冲是否已经满了。

Ken Wang：

看你的描述，像是使能了串口发送中断。可以的话，检查一下你的UART初始化程序。

谢谢

Hayden：

回复 Ken Wang:

你好，串口部分初始化代码如下：

// // Configure the UART for 115,200, 8-N-1 operation. // ROM_UARTConfigSetExpClk(UART0_BASE, ui32SysClock, 115200, (UART_CONFIG_WLEN_8 | UART_CONFIG_STOP_ONE | UART_CONFIG_PAR_NONE));

// // Enable the UART interrupt. // ROM_IntEnable(INT_UART0); ROM_UARTIntEnable(UART0_BASE, UART_INT_RX | UART_INT_RT);

根据代码使能的应该是接收中断和接收超时中断，如果调用一次UARTSend();可以进入一次中断函数，

不明白为何与UARTSend（）有关系？

谢谢你的指导！

Ken Wang：

回复 Hayden:

你可以查看一下在中断响应函数里面Status = UARTIntStatus(UART0_BASE, 1);的staus的值，看下是中断标志位，确定接收中断的标志位情况。

毕竟ＵＡＲＴ的接收和发送中断的响应函数是一个。

Hayden：

回复 Ken Wang:

Hi, Ken

如果使能下面这句，可以每次进入中断，获取到的Status = UARTIntStatus(UART0_BASE, 1);为0x0040（即是UART_INT_RT）；

ROM_UARTCharPutNonBlocking(UART0_BASE, UARTCharGetNonBlocking(UART0_BASE));

如果使用ROM_UARTIntEnable(）使能UART_INT_RX或者 UART_INT_TX，从未在中断中判断到这两个中断标志，也没有进入过中断，

这种情况如何解决，我的目的只是在中断中接收数据保存起来，如下：

voidUARTIntHandler(void){ uint32_t ui32Status;

// // Get the interrrupt status. // ui32Status = ROM_UARTIntStatus(UART0_BASE, true);

// // Clear the asserted interrupts. // ROM_UARTIntClear(UART0_BASE, ui32Status);

// // Loop while there are characters in the receive FIFO. // while(ROM_UARTCharsAvail(UART0_BASE)) { temp = UARTCharGetNonBlocking(UART0_BASE); }}

如果你身边有板子，麻烦你测试一下这个问题，

非常感谢！

Ken Wang：

回复 Hayden:

我手上没有1294的板子，就用123GH6PGE的板子测了一下，程序每次都能进中断，你可以参考一下：

//*****************************************************************************
//
// uart_echo.c - Example for reading data from and writing data to the UART in
//an interrupt driven fashion.
//
// Copyright (c) 2011-2014 Texas Instruments Incorporated.All rights reserved.
// Software License Agreement
//
// Texas Instruments (TI) is supplying this software for use solely and
// exclusively on TI's microcontroller products. The software is owned by
// TI and/or its suppliers, and is protected under applicable copyright
// laws. You may not combine this software with "viral" open-source
// software in order to form a larger program.
//
// THIS SOFTWARE IS PROVIDED "AS IS" AND WITH ALL FAULTS.
// NO WARRANTIES, WHETHER EXPRESS, IMPLIED OR STATUTORY, INCLUDING, BUT
// NOT LIMITED TO, IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE APPLY TO THIS SOFTWARE. TI SHALL NOT, UNDER ANY
// CIRCUMSTANCES, BE LIABLE FOR SPECIAL, INCIDENTAL, OR CONSEQUENTIAL
// DAMAGES, FOR ANY REASON WHATSOEVER.
//
// This is part of revision 2.1.0.12573 of the DK-TM4C123G Firmware Package.
//
//*****************************************************************************#include <stdint.h>
#include <stdbool.h>
#include "inc/hw_ints.h"
#include "inc/hw_memmap.h"
#include "driverlib/debug.h"
#include "driverlib/fpu.h"
#include "driverlib/gpio.h"
#include "driverlib/interrupt.h"
#include "driverlib/sysctl.h"
#include "driverlib/uart.h"
#include "driverlib/rom.h"
#include "grlib/grlib.h"
#include "drivers/cfal96x64x16.h"//*****************************************************************************
//
//! \addtogroup example_list
//! <h1>UART Echo (uart_echo)</h1>
//!
//! This example application utilizes the UART to echo text.The first UART
//! (connected to the USB debug virtual serial port on the evaluation board)
//! will be configured in 115,200 baud, 8-n-1 mode.All characters received on
//! the UART are transmitted back to the UART.
//
//*****************************************************************************//*****************************************************************************
//
// The error routine that is called if the driver library encounters an error.
//
//*****************************************************************************
#ifdef DEBUG
void
__error__(char *pcFilename, uint32_t ui32Line)
{
}
#endif//*****************************************************************************
//
// The UART interrupt handler.
//
//*****************************************************************************
void
UARTIntHandler(void)
{uint32_t ui32Status;uint8_t Temp;//// Get the interrrupt status.//ui32Status = ROM_UARTIntStatus(UART0_BASE, true);//// Clear the asserted interrupts.//ROM_UARTIntClear(UART0_BASE, ui32Status);//// Loop while there are characters in the receive FIFO.//while(ROM_UARTCharsAvail(UART0_BASE)){//// Read the next character from the UART and write it back to the UART.////ROM_UARTCharPutNonBlocking(UART0_BASE,//ROM_UARTCharGetNonBlocking(UART0_BASE));Temp = ROM_UARTCharGetNonBlocking(UART0_BASE);}
}//*****************************************************************************
//
// Send a string to the UART.
//
//*****************************************************************************
void
UARTSend(const uint8_t *pui8Buffer, uint32_t ui32Count)
{//// Loop while there are more characters to send.//while(ui32Count--){//// Write the next character to the UART.//ROM_UARTCharPutNonBlocking(UART0_BASE, *pui8Buffer++);}
}//*****************************************************************************
//
// This example demonstrates how to send a string of data to the UART.
//
//*****************************************************************************
int
main(void)
{tRectangle sRect;tContext sContext;//// Enable lazy stacking for interrupt handlers.This allows floating-point// instructions to be used within interrupt handlers, but at the expense of// extra stack usage.//ROM_FPULazyStackingEnable();//// Set the clocking to run directly from the crystal.//ROM_SysCtlClockSet(SYSCTL_SYSDIV_1 | SYSCTL_USE_OSC | SYSCTL_OSC_MAIN |SYSCTL_XTAL_16MHZ);//// Initialize the display driver.//CFAL96x64x16Init();//// Initialize the graphics context.//GrContextInit(&sContext, &g_sCFAL96x64x16);//// Fill the top part of the screen with blue to create the banner.//sRect.i16XMin = 0;sRect.i16YMin = 0;sRect.i16XMax = GrContextDpyWidthGet(&sContext) - 1;sRect.i16YMax = 9;GrContextForegroundSet(&sContext, ClrDarkBlue);GrRectFill(&sContext, &sRect);//// Change foreground for white text.//GrContextForegroundSet(&sContext, ClrWhite);//// Put the application name in the middle of the banner.//GrContextFontSet(&sContext, g_psFontFixed6x8);GrStringDrawCentered(&sContext, "uart-echo", -1,GrContextDpyWidthGet(&sContext) / 2, 4, 0);//// Initialize the display and write some instructions.//GrStringDrawCentered(&sContext, "Connect a", -1,GrContextDpyWidthGet(&sContext) / 2, 20, false);GrStringDrawCentered(&sContext, "terminal", -1,GrContextDpyWidthGet(&sContext) / 2, 30, false);GrStringDrawCentered(&sContext, "to UART0.", -1,GrContextDpyWidthGet(&sContext) / 2, 40, false);GrStringDrawCentered(&sContext, "115000,N,8,1", -1,GrContextDpyWidthGet(&sContext) / 2, 50, false);//// Enable the peripherals used by this example.//ROM_SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOA);ROM_SysCtlPeripheralEnable(SYSCTL_PERIPH_UART0);//// Enable processor interrupts.//ROM_IntMasterEnable();//// Set GPIO A0 and A1 as UART pins.//ROM_GPIOPinTypeUART(GPIO_PORTA_BASE, GPIO_PIN_0 | GPIO_PIN_1);//// Configure the UART for 115,200, 8-N-1 operation.//ROM_UARTConfigSetExpClk(UART0_BASE, ROM_SysCtlClockGet(), 115200,(UART_CONFIG_WLEN_8 | UART_CONFIG_STOP_ONE |UART_CONFIG_PAR_NONE));//// Enable the UART interrupt.//ROM_IntEnable(INT_UART0);ROM_UARTIntEnable(UART0_BASE, UART_INT_RX | UART_INT_RT);//// Prompt for text to be entered.//UARTSend((uint8_t *)"Enter text: ", 12);//// Loop forever echoing data through the UART.//while(1){}
}

Hayden：

回复 Ken Wang:

Hi,Ken

谢谢你，我再找找问题，有解决方法我贴出来；如果你拿到129的板子，也麻烦你验证一下！

Hayden：

回复 Ken Wang:

Hi,Ken

经过测试发现：不是代码的问题，应该是串口电平匹配的问题，我使用板载的Debugger的串口调试是进不了中断的，使用外部的RS232转TTL(max3232)可以正常进入中断，测试过两块TM4C129X Developmet Board都是这样的情况。所以我判断应该是板载的usb转串口电平与MCU IO不匹配，不知你有什么见解？

谢谢！