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我用TM4C123测试了一下,加了
while(ROM_UARTBusy(UART0_BASE))//add by susan
{
// delay here until transmission is complete
}
可以成功发送,代码如下
//***************************************************************************** // // uart_echo.c - Example for reading data from and writing data to the UART in // an interrupt driven fashion. // // Copyright (c) 2012-2017 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 2.1.4.178 of the EK-TM4C123GXL 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/pin_map.h" #include "driverlib/rom.h" #include "driverlib/sysctl.h" #include "driverlib/uart.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; // // 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)); // // Blink the LED to show a character transfer is occuring. // GPIOPinWrite(GPIO_PORTF_BASE, GPIO_PIN_2, GPIO_PIN_2); // // Delay for 1 millisecond. Each SysCtlDelay is about 3 clocks. // SysCtlDelay(SysCtlClockGet() / (1000 * 3)); // // Turn off the LED // GPIOPinWrite(GPIO_PORTF_BASE, GPIO_PIN_2, 0); } } //***************************************************************************** // // 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++); } while(ROM_UARTBusy(UART0_BASE))//add by susan { // delay here until transmission is complete } } //***************************************************************************** // // This example demonstrates how to send a string of data to the UART. // //***************************************************************************** int main(void) { // // 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_FPUEnable(); 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); // // Enable the GPIO port that is used for the on-board LED. // ROM_SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOF); // // Enable the GPIO pins for the LED (PF2). // ROM_GPIOPinTypeGPIOOutput(GPIO_PORTF_BASE, GPIO_PIN_2); // // Enable the peripherals used by this example. // ROM_SysCtlPeripheralEnable(SYSCTL_PERIPH_UART0); ROM_SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOA); // // Enable processor interrupts. // ROM_IntMasterEnable(); // // Set GPIO A0 and A1 as UART pins. // GPIOPinConfigure(GPIO_PA0_U0RX); GPIOPinConfigure(GPIO_PA1_U0TX); 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 *)"\033[2JEnter text: ", 16); // // Loop forever echoing data through the UART. // while(1) { } }
您好, 我明白了。下面是部分代码,单字节发送:
(1)while(1)
{
if(Uart2RX_OK==1)
{
Slave_B(Rx_Uart[UART2].RxBuffer,Rx_Uart[UART2].InPointer,UART2);
}
}
(2)void Slave_B(uint8_t * ComRecBuffer,uint16_t Length,int iPort)
{
if(ComRecBuffer[0]==Rx_Uart[iPort].self_Addr)
{
Tempaddr=(ComRecBuffer[2]<<8)+ComRecBuffer[3];
Templen=(ComRecBuffer[4]<<8)+ComRecBuffer[5];
if(ComRecBuffer[1]==0x03)
{
dataClass=CheckAdde(Tempaddr,Tempaddr+Templen-1);
if(send_count_B==0)
{
YC_YX(Tempaddr,Templen,iPort,ComRecBuffer[1],dataClass);
}
else
{
if(send_count_B<Templen*2+5)
{
YC_YX(Tempaddr,Templen,iPort,ComRecBuffer[1],dataClass);
}
else
{
send_count_B=0;
Uart2RX_OK=0;
Rx_Uart[iPort].RxCounter=0;
Rx_Uart[iPort].InPointer=0;
}
}
}
}
}
(3)void Pack_YC_YX_Modbus(uint16_t StartValue,uint16_t Length,int iPort,uint8_t FCCode,uint16_t DataClass)
{
unsigned int i=0;
uint16_t getvalue;
unsigned int CRCValue=0;
Command[0]=Rx_Uart[iPort].self_Addr;
Command[1]=FCCode;
Command[2]=Length*2;
for(i=0; i<Length; i++)
{
getvalue=SearchDataValue(StartValue+i,DataClass);
Command[3+2*i] = (getvalue>>8)&0xff;
Command[3+2*i+1] = getvalue&0xff;
}
CRCValue=CRC16(Command,Length*2+3);
Command[Length*2+3]=(CRCValue>>8)&0xff;
Command[Length*2+4]=CRCValue&0xff;
if(iPort==UART2)
{
if(send_count_B<Length*2+5)
{
TxFIFOFill_UART2(iPort,Command[send_count_B],1);
send_count_B++;
}
}
else if(iPort==UART6)
{
if(send_count_D<Length*2+5)
{
TxFIFOFill_UART6(iPort,Command[send_count_D],1);
send_count_D++;
}
}
else
{
;
}
}
(4)void TxFIFOFill_UART2(int iport,unsigned char SendCode,unsigned int Length)
{
unsigned int j=0,my_length;
my_length=Length;
UART2ENABLETX;
ROM_UARTCharPutNonBlocking(UART2_BASE, SendCode);//发送UARTCharPut ROM_UARTCharPut
while(ROM_UARTBusy(UART2_BASE))//add by susan
{
// delay here until transmission is complete
}
UART2DISABLETX;
}
我的问题是:上述代码是UART2的执行过程,UART3与UART2执行过程和方法一致,如果中断来临时间点基本一致的话(未配置中断优先级),两个串口的输出从测试结果来看,UART3的输出必须是在等UART2完成后才执行。
上图1~6的执行是否占用CPU的资源呢?
抱歉,之前miss掉了您这个帖子
pei gong 说:这两个FIFO都是通过寄存器UARTDR来访问的,那要是两个独立的UART,如果是同时响应了中断后,FIFO处理时是不能同时处理的是吧
您的理解是正确的,并且如您之前所说这个函数的执行是占用CPU时间的
FIFO的原理和使用都是类似的,网络上有一些讲解的文章,您可以看一下
https://blog.csdn.net/houqi02/article/details/51683635
https://blog.csdn.net/wxc971231/article/details/95624942
另外建议用中断处理方式,根据需求设定FIFO中断级位,SCIFFRX中的RXFFIL设置接收中断,cpu接收到一定数目的字符后去读FIFO中的数据,避免数据丢失。