str9 UART

[s_bhujbal]

Posted on April 15, 2008 at 05:59

str9 UART

[s_bhujbal]

Posted on May 17, 2011 at 09:52

Dear All,

I am using UART0 of STR9, I am abled to transmit the data to PC. I have made one simple function which takes string as input & transmits data byte by byte on UART with help of ST library function UART_SendData().

When I calls that function through while( 1 ), it gives junk chars on PC. Other every thing is right i.e. baud rate & other parameters on both ends. I tried to check busy flag to let UART transmit data completely, I have also tried other flags also like FIFO Empty/Full flag, but still it is giving junk chars at PC end.

I will be very thankful if anybody tell me the solution.

:-[

[jpeacock2]

Posted on May 17, 2011 at 09:52

''Garbage characters'' is usually a sign of a mismatch in baud rates or word size. Are you sure the clock source is at the frequency you think it is?

[s_bhujbal]

Posted on May 17, 2011 at 09:52

Yes FIFOs are enabled

[michael]

Posted on May 17, 2011 at 09:52

are you FIFOs working?

[s_bhujbal]

Posted on May 17, 2011 at 09:52

Dear Michael & JakBird Thanks for replying,

I am using Library given by ST. If I print string through before while it gets on PC properly therefore I think that baud rate setting is not problem. My code is as follows after configuring PLL for 96MHz.

/* Enable the UART0 Clock */

SCU_APBPeriphClockConfig(__UART0, ENABLE);

/* UART Initialization */

UART_InitStructure.UART_WordLength = UART_WordLength_8D;

UART_InitStructure.UART_StopBits = UART_StopBits_1;

UART_InitStructure.UART_Parity = UART_Parity_No ;

UART_InitStructure.UART_BaudRate = 9600;

UART_InitStructure.UART_HardwareFlowControl = UART_HardwareFlowControl_None;

UART_InitStructure.UART_Mode = UART_Mode_Tx_Rx;

UART_InitStructure.UART_FIFO = UART_FIFO_Enable;

UART_InitStructure.UART_TxFIFOLevel = UART_FIFOLevel_1_2; /* FIFO size 16 bytes, FIFO level 8 bytes */

UART_InitStructure.UART_RxFIFOLevel = UART_FIFOLevel_1_2; /* FIFO size 16 bytes, FIFO level 8 bytes */

UART_DeInit(UART0);

UART_Init(UART0, &UART_InitStructure);

/* Enable the UART0 */

UART_Cmd(UART0, ENABLE);

/* Following is the code in main */

sprintf( acString,''Any String'');

Uart0printf( acString ); <----This line works properly

while ( 1 )

{

Uart0printf( acString ); <----This line doesn't work properly

}

Following is the function which I am using for printing a string

void Uart0printf( char *pcString )

{

while( *pcString != '\n' )

{

UART_SendData( UART0, *pcString);

while(UART_GetFlagStatus(UART0, UART_FLAG_TxFIFOFull) != RESET);

At above position I have also tried some other flags & there SET, RESET values, even UART_Clear function also used

pcString++;

}//while

}//Uart0printf

Please tell me if any mistake in above code.

[michael]

Posted on May 17, 2011 at 09:52

post your register values please.

[s_bhujbal]

Posted on May 17, 2011 at 09:52

Dear All,

Problem is solved. Mistake was in checking '\n' in place of NULL. After correcting it I just added ''while(UART_GetFlagStatus(UART0, UART_FLAG_TxFIFOFull) != RESET);'' after char send API. Now it is working fine in while also.

Thanks

:D