Hello Community,
I have a problem and I hope you can help me. I have started programming on the Evaluation Board LM4F232. On this board, I want to use the UART interface. I have tried to understand the UART_Echo program. Everything works fine, but if I change the baud rate from 115200 to 9600 (what I need). The UART interface don't send an Echo to the PC.
First I thought the PC does the problem, so I have tried others. But it doesn't works too ....
I use CCS v5.4.0.00091
And the Code: (it's the same as the UART_Echo but with another baud rate)
//*****************************************************************************
//
// uart_echo.c - Example for reading data from and writing data to the UART in
// an interrupt driven fashion.
//
// Copyright (c) 2011 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 8049 of the EK-LM4F232 Firmware Package.
//
//*****************************************************************************
#include "inc/hw_ints.h"
#include "inc/hw_memmap.h"
#include "inc/hw_types.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, unsigned long ulLine)
{
}
#endif
//*****************************************************************************
//
// The UART interrupt handler.
//
//*****************************************************************************
void
UARTIntHandler(void)
{
unsigned long ulStatus;
//
// Get the interrrupt status.
//
ulStatus = ROM_UARTIntStatus(UART0_BASE, true);
//
// Clear the asserted interrupts.
//
ROM_UARTIntClear(UART0_BASE, ulStatus);
//
// 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));
}
}
//*****************************************************************************
//
// Send a string to the UART.
//
//*****************************************************************************
void
UARTSend(const unsigned char *pucBuffer, unsigned long ulCount)
{
//
// Loop while there are more characters to send.
//
while(ulCount--)
{
//
// Write the next character to the UART.
//
ROM_UARTCharPutNonBlocking(UART0_BASE, *pucBuffer++);
}
}
//*****************************************************************************
//
// This example demonstrates how to send a string of data to the UART.
//
//*****************************************************************************
int
main(void)
{
tRectangle sRect;
tContext sContext;
//
// The FPU should be enabled because some compilers will use floating-
// point registers, even for non-floating-point code. If the FPU is not
// enabled this will cause a fault. This also ensures that floating-
// point operations could be added to this application and would work
// correctly and use the hardware floating-point unit. Finally, lazy
// stacking is enabled for interrupt handlers. This allows floating-
// point instructions to be used within interrupt handlers, but at the
// expense of extra stack usage.
//
FPUEnable();
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.sXMin = 0;
sRect.sYMin = 0;
sRect.sXMax = GrContextDpyWidthGet(&sContext) - 1;
sRect.sYMax = 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_pFontFixed6x8);
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(), 9600,
(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((unsigned char *)"Enter text: ", 12);
//
// Loop forever echoing data through the UART.
//
while(1)
{
}
}
