C8051F040出现重大问题

只看该作者 · 2010-11-2 17:01

我使用了C8051F040 MCU，在做串口编程时，屡屡失败，后来我就写了一个最基本的小程序，只更改SBUF0的值，一调试发现就是写不进值去，程序如下：

void main(void){
WDT_Disable; /*disable watchdog*/
SFRPAGE=0x0F;
OSCICN=0x83; /*internal clock,24.5MHz*/
SFRPAGE=0;
SBUF0=0xFF;/*这里就是写不进值去，还是0x00*/
while(1);
... ........
}

只看该作者 · 2010-11-2 17:03

我使用的是新华龙的C8051F040和它的仿真器，写别的寄存器是没有问题的，如下：
SFRPAGE=0;
SADDR0=0xFF; /*能写进去，没有任何问题*/

但是为什么写SBUF0就是不行，我发不出数据去啊？！

救命啊。。。

只看该作者 · 2010-11-2 18:20

你最好用示波器测一下，说不定等你停下来看的时候SBUF0的数据已经发出去了

4万 · 2010-11-2 19:04

检查波特率发生器是否启动和正确配置。

只看该作者 · 2010-11-2 20:26

我使用了Timer3作为UART0的波特率发生器,自动装载模式,并且启动了TR3,但是结果就是写不进值去.
示波器? 根本不用看,单步执行的时候卡在这里,示波器肯定显示不出来.

1万 · 2010-11-3 08:47

"
最好通知SILABS公司
说不定还能有个奖励什么的
"

只看该作者 · 2010-11-3 09:22

SBUF0读和写是对应于两个寄存器，读的是接收寄存器，写的是发送寄存器，IDE中看到的值应该是接收寄存器

只看该作者 · 2011-4-8 16:22

请问你现在解决了吗？如何解决的？我也遇到这个问题了，真郁闷~~

只看该作者 · 2011-4-8 16:42

应该没问题啊我天天用啊挺好的啊

要么你先禁止接收然后发送然后允许接收试试

只看该作者 · 2011-4-8 16:46

//-----------------------------------------------------------------------------
// F04x_UART0_INT.c
//-----------------------------------------------------------------------------
// Copyright 2006 Silicon Laboratories, Inc.
// http://www.silabs.com
//
// Program Description:
//
// This program demonstrates how to configure the C8051F040 to write to and read
// from the UART interface. The program reads a word using the UART0 interrupts
// and outputs that word to the screen, with all characters in uppercase
//
// How To Test:
//
// 1) Download code to a 'F04x device that is connected to a UART transceiver
// 2) Verify jumpers J6 and J9 are populated on the 'F04x TB.
// 3) Connect serial cable from the transceiver to a PC
// 4) On the PC, open HyperTerminal (or any other terminal program) and connect
// to the COM port at <BAUDRATE> and 8-N-1
// 5) Type up to 64 characters into the Terminal and press Enter.  The MCU
// will then print back the characters that were typed
//
//
// Target:       C8051F04x
// Tool chain:    Keil C51 7.50 / Keil EVAL C51
// Command Line: None
//
// Release 1.0
// -Initial Revision (SM)
// -10 JULY 2007
//

//-----------------------------------------------------------------------------
// Includes
//-----------------------------------------------------------------------------

#include <C8051F040.h>                // SFR declarations
#include <stdio.h>

//-----------------------------------------------------------------------------
// 16-bit SFR Definitions for 'F04x
//-----------------------------------------------------------------------------

sfr16 RCAP2 = 0xCA;                // Timer2 capture/reload
sfr16 TMR2    = 0xCC;                // Timer2

//-----------------------------------------------------------------------------
// Global Constants
//-----------------------------------------------------------------------------

#define BAUDRATE    115200          // Baud rate of UART in bps

// SYSTEMCLOCK = System clock frequency in Hz
#define SYSTEMCLOCK    22118400L

//-----------------------------------------------------------------------------
// Function Prototypes
//-----------------------------------------------------------------------------

void OSCILLATOR_Init (void);
void PORT_Init (void);
void UART0_Init (void);

//-----------------------------------------------------------------------------
// Global Variables
//-----------------------------------------------------------------------------

#define UART_BUFFERSIZE 64
unsigned char UART_Buffer[UART_BUFFERSIZE];
unsigned char UART_Buffer_Size = 0;
unsigned char UART_Input_First = 0;
unsigned char UART_Output_First = 0;
unsigned char TX_Ready =1;
static char Byte;

//-----------------------------------------------------------------------------
// main() Routine
//-----------------------------------------------------------------------------

void main (void)
{
SFRPAGE = CONFIG_PAGE;

WDTCN = 0xDE;                      // Disable watchdog timer
WDTCN = 0xAD;

OSCILLATOR_Init ();                // Initialize oscillator
PORT_Init ();                      // Initialize crossbar and GPIO

UART0_Init ();                   // Initialize UART0

EA = 1;

SFRPAGE = UART0_PAGE;

while (1)
{
   // If the complete word has been entered via the terminal followed
   // by carriage return
   if((TX_Ready == 1) && (UART_Buffer_Size != 0) && (Byte == 13))
   {
      TX_Ready = 0;                // Set the flag to zero
      TI0 = 1;                      // Set transmit flag to 1
   }
}
}

//-----------------------------------------------------------------------------
// Initialization Subroutines
//-----------------------------------------------------------------------------

//-----------------------------------------------------------------------------
// OSCILLATOR_Init
//-----------------------------------------------------------------------------
//
// Return Value : None
// Parameters : None
//
// This function initializes the system clock to use an external 22.1184MHz
// crystal.
//
//-----------------------------------------------------------------------------
void OSCILLATOR_Init (void)
{
int i;                            // Software timer

char SFRPAGE_SAVE = SFRPAGE;       // Save Current SFR page

SFRPAGE = CONFIG_PAGE;             // Set SFR page

OSCICN = 0x80;                   // Set internal oscillator to run
                                    // at its slowest frequency

CLKSEL = 0x00;                   // Select the internal osc. as
                                    // the SYSTEMCLOCK source

// Initialize external crystal oscillator to use 22.1184 MHz crystal

OSCXCN = 0x67;                   // Enable external crystal osc.
for (i=0; i < 256; i++);          // Wait at least 1ms

while (!(OSCXCN & 0x80));          // Wait for crystal osc to settle

CLKSEL = 0x01;
// Select external crystal as SYSTEMCLOCK source

SFRPAGE = SFRPAGE_SAVE;          // Restore SFRPAGE
}

//-----------------------------------------------------------------------------
// PORT_Init
//-----------------------------------------------------------------------------
//
// Return Value : None
// Parameters : None
//
// This function configures the crossbar and GPIO ports.
//
// Pinout:
//
// P0.0 digital push-pull    UART TX
// P0.1 digital open-drain UART RX
// P1.6 digital push-pull    LED
//-----------------------------------------------------------------------------
void PORT_Init (void)
{
char SFRPAGE_SAVE = SFRPAGE;       // Save Current SFR page

SFRPAGE = CONFIG_PAGE;             // Set SFR page

XBR0    = 0x04;                   // Enable UART0
XBR1    = 0x00;
XBR2    = 0x40;                   // Enable crossbar and weak pull-up

P0MDOUT |= 0x01;                   // Set TX pin to push-pull
P1MDOUT |= 0x40;                   // Set P1.6(LED) to push-pull

SFRPAGE = SFRPAGE_SAVE;          // Restore SFR page
}

//-----------------------------------------------------------------------------
// UART0_Init Variable baud rate, Timer 2, 8-N-1
//-----------------------------------------------------------------------------
//
// Return Value : None
// Parameters : None
//
// Configure UART0 for operation at <BAUDRATE> 8-N-1 using Timer2 as
// baud rate source.
//
//-----------------------------------------------------------------------------
void UART0_Init (void)
{
char SFRPAGE_SAVE;

SFRPAGE_SAVE = SFRPAGE;          // Preserve SFRPAGE

SFRPAGE = TMR2_PAGE;

TMR2CN = 0x00;                   // Timer in 16-bit auto-reload up timer
                                    // mode
TMR2CF = 0x08;                   // SYSCLK is time base; no output;
                                    // up count only
RCAP2 = - ((long) SYSTEMCLOCK/BAUDRATE/16);
TMR2 = RCAP2;
TR2= 1;                            // Start Timer2

SFRPAGE = UART0_PAGE;

SCON0 = 0x50;                      // 8-bit variable baud rate;
                                    // 9th bit ignored; RX enabled
                                    // clear all flags
SSTA0 = 0x15;                      // Clear all flags; enable baud rate
                                    // doubler (not relevant for these
                                    // timers);
                                    // Use Timer2 as RX and TX baud rate
                                    // source;
ES0 = 1;
IP |= 0x10;
SFRPAGE = SFRPAGE_SAVE;          // Restore SFRPAGE
}

//-----------------------------------------------------------------------------
// Interrupt Service Routines
//-----------------------------------------------------------------------------

//-----------------------------------------------------------------------------
// UART0_Interrupt
//-----------------------------------------------------------------------------
//
// This routine is invoked whenever a character is entered or displayed on the
// Hyperterminal.
//
//-----------------------------------------------------------------------------

void UART0_Interrupt (void) interrupt 4
{
SFRPAGE = UART0_PAGE;

if (RI0 == 1)
{
   // Check if a new word is being entered
   if( UART_Buffer_Size == 0) {
      UART_Input_First = 0; }

   RI0 = 0;
   Byte = SBUF0; // Read a character from Hyperterminal

   if (UART_Buffer_Size < UART_BUFFERSIZE)
   {
      UART_Buffer[UART_Input_First] = Byte;

      UART_Buffer_Size++;          // Update array's size

      UART_Input_First++;          // Update counter
   }
}

if (TI0 == 1)          // Check if transmit flag is set
{
   TI0 = 0;

   if (UART_Buffer_Size != 1)       // If buffer not empty
   {
      // Check if a new word is being output
      if ( UART_Buffer_Size == UART_Input_First )  {
            UART_Output_First = 0; }

      Byte = UART_Buffer[UART_Output_First];

      if ((Byte >= 0x61) && (Byte <= 0x7A)) { // If upper case letter
         Byte -= 32; }

      SBUF0 = Byte;                // Transmit to Hyperterminal

      UART_Output_First++;          // Update counter

      UART_Buffer_Size--;             // Decrease array size
   }
   else
   {
      UART_Buffer_Size = 0;       // Set the array size to 0
      TX_Ready = 1;                // Transmission complete
   }
}
}

//-----------------------------------------------------------------------------
// End Of File
//-----------------------------------------------------------------------------