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Visitor eimazm
Visitor
5,788 Views
Registered: ‎07-23-2014

Set UART baudrate to 921600 bps

How can i set the baudrate of UART to 921600 bps????

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3 Replies
Xilinx Employee
Xilinx Employee
5,780 Views
Registered: ‎08-02-2007

Re: Set UART baudrate to 921600 bps

Hi,

 

Looking at the xuartps.h it looks that we can change the parameters to make the UART PS work at a higher baud rate. Modify these parameters as a custom driver and test it

/*
* The following constants indicate the max and min baud rates and these
* numbers are based only on the testing that has been done. The hardware
* is capable of other baud rates.
*/
#define XUARTPS_MAX_RATE 115200
#define XUARTPS_MIN_RATE 110

#define XUARTPS_DFT_BAUDRATE 115200 /* Default baud rate */

 

xuartps.h is a part of the uartps drivers folder.

 

--Hem

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Contributor
Contributor
5,355 Views
Registered: ‎04-17-2012

Re: Set UART baudrate to 921600 bps

Hello,

I have the same question. I modified those parameters manually but it seems the Zedboard is still sending data @ 115200. 

I tried even slower baud rates but the same, any suggestion please?

 

 


Best,
L30nardo SV
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Observer madison_a
Observer
5,310 Views
Registered: ‎06-13-2014

Re: Set UART baudrate to 921600 bps

The short version is depending upon which u-boot/kernel you're running, you'll likely have to modify the source code. I happened upon this issue because my system is running an atypical system clock speed, and found that the older source doesn't actually find the device driver.

 

The critical error message for this version of source is:

 

xuartps ... failed to get alias id, errno -19

 

The code then uses a hard coded value for the divided clock speed supplied to the uart, which later is translated into the baudrate. You may also, as you have already done, modified the defines for t he desired baudrate.

 

 

 

 

 

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