The compiler includes the source code to the library routines, so you
should be able to figure out what's going on.  Though I would suggest
that instead of spending time on that, don't use the library routines,
and use the time to learn how the UART works and to write your own
code.

On Mon, 6 Feb 2006, Vitaliy wrote:

> Guys, there wasn't a single reply -- did this post make it to the list?
>
>
> ----- Original Message -----
> From: "Vitaliy" <spam@maksimov.org>
> To: "piclist" <PICLIST@mitvma.mit.edu>
> Sent: Monday, February 06, 2006 5:45 AM
> Subject: [PIC]: putrsUSART() breaking DataRdyUSART()
>
>
>> Hello List,
>>
>> I have a little circuit which uses a PIC18F4320, whose Tx/Rx lines are
>> tied
>> together (Tx is connected through a diode, so it can only drive the bus
>> low). It's very similar to the Parallax AppMods.
>>
>> Now, any time I use putrsUSART(), it causes the DataRdyUSART() function to
>> stop working. I attached the source code to this message. If you were to
>> compile and run it as-is, and type "ABCDEFG" in HyperTerminal, you would
>> see:
>>
>>    AABBCCDDEEFFGG
>>
>> However, if you were to uncomment the putrsUSART() function, you would
>> get:
>>
>>    Hello World!
>>
>>    ABCDEFG
>>
>> For some reason, after the putrsUSART() function is used, DataRdyUSART()
>> never evaluates to TRUE.
>>
>> A couple of observations:
>>
>> 1. Closing/opening the port after using the putrsUSART() fixes the
>> problem.
>> 2. putcUSART() does not have this issue.
>>
>> I have a feeling that I am overlooking something very obvious. Any help
>> with
>> this matter is greatly appreciated!
>>
>> Best regards,
>>
>> Vitaliy
>>
>> ---------- Source Code -------------------
>>
>> #include <p18f4320.h>
>> #include <delays.h>
>> #include <usart.h>
>>
>> /* Set configuration bits for use with ICD2 / PICDEM2 PLUS Demo Board:
>> *  - set HS-PLL oscillator
>> *  - disable watchdog timer
>> *  - disable low voltage programming
>> *  - enable background debugging
>> */
>>
>> #pragma config OSC = HSPLL
>> #pragma config WDT = OFF
>> #pragma config LVP = OFF
>> #pragma config DEBUG = ON
>>
>> void main(void)
>> {
>>  char c;
>>
>>   //Open the USART configured as 8N1 in polled mode
>>  OpenUSART (USART_TX_INT_OFF &
>>               USART_RX_INT_OFF &
>>               USART_ASYNCH_MODE &
>>               USART_EIGHT_BIT &
>>               USART_CONT_RX &
>>               USART_BRGH_LOW, 255);
>>
>>  //putrsUSART((const far rom char *)"\rHello World!\r");
>>
>>  while (BusyUSART()); // wait until transmission is complete
>>
>>   for (;;)
>>   {
>>      if (DataRdyUSART())  // check USART read buffer
>>      {
>>         c = getcUSART();           // read character
>>         putcUSART(c);              // echo it back
>>         while (BusyUSART());       // wait until transmission is complete
>>         Delay1KTCYx(4);            // wait some more
>>         while (DataRdyUSART())     // empty the receive buffer
>>            getcUSART();
>>      }
>>   }
>> }
>
> -- 
> http://www.piclist.com PIC/SX FAQ & list archive
> View/change your membership options at
> http://mailman.mit.edu/mailman/listinfo/piclist
>

--
John W. Temples, III
-- 
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist