UART0 Baudrate problem

tj2 · ‎2005-10-03

Posted on October 04, 2005 at 05:17

tj2 · ‎2005-10-03

Posted on October 03, 2005 at 14:30

Hi

I've compiled the AN1797 example and tried it on the evaluation board. This works fine. The board echo back all characterers send from Hyperterminal.

I then program the same example into our own target board. But the baudrate seems to wrong. Our target board uses a 4MHz crystal, but the UART_Config function uses the RCCU_FrequencyValue to calculate the baudrate on runtime. So the crystal frequency should not be the problem or is it?

rsherry · ‎2005-10-03

Posted on October 03, 2005 at 14:42

Double check your 71x_conf.h header for a proper definition of RCCU_Main_Osc. This is necessary for the Library to calculate a proper baud value. You should see something like...

/* Main Oscillator Frequency value = 4 Mhz */

#define RCCU_Main_Osc 4000000

Best regards,

Ryan.

tj2 · ‎2005-10-03

Posted on October 03, 2005 at 15:03

thx...

I had to remove ''extern const u32 RCCU_Main_Osc;'' from the RCCU.h file to be able to compile. - But it didn't work. Same symptoms as before.

sjo · ‎2005-10-03

Posted on October 03, 2005 at 16:27

Sounds like you are using the Anglia SARM Toolchain whicj uses a differant method than the standard libs. If so the definition for the RCCU_Main_Osc is at the top of your startup file - should be startup.s by deafult.

Regards

sjo

tj2 · ‎2005-10-03

Posted on October 04, 2005 at 05:17

Yes, Im using the Anglia SARM Toolchain. I've found the constant in the startup.s file. And now it works!

@ SJO - Thank you very much for your help!