UART Clock Warning

Tip / Sign in to post questions, reply, level up, and achieve exciting badges. Know more

cross mob
Anonymous
Not applicable

Hello,

   

I've included the standard UART block in my project and configured it with baud rate 115200, external interrupt, RX FIFO not empty.

   

I'm getting the following warning. I don't get the warning if I reduce the baud rate to the one lower. But we need the 115200 for our project. Can you please help me to get rid of this warning?

   

Clock Warning: (WiFi_Host_SCBCLK's accuracy range '1.333 MHz +/- 2%, (1.307 MHz - 1.36 MHz)' is not within the specified tolerance range '1.382 MHz +/- 5%, (1.313 MHz - 1.452 MHz)'.).

   

Thanks & Regards,

   

Sharan

0 Likes
1 Solution
Bob_Marlowe
Level 10
Level 10
First like given 50 questions asked 10 questions asked

Set the IMO to 18MHz.

   

A tip: set UART to byte mode.

   

 

   

Bob

View solution in original post

0 Likes
11 Replies
Bob_Marlowe
Level 10
Level 10
First like given 50 questions asked 10 questions asked

Can you please post your complete project, so that we all can have a look at all of your settings. To do so, use
Creator->File->Create Workspace Bundle (minimal)
and attach the resulting file.

   

 

   

Bob

0 Likes
lock attach
Attachments are accessible only for community members.
Anonymous
Not applicable

Hi Bob,

   

Attached the test workspace.

   

Thanks & Regards,

   

Sharan

0 Likes
Bob_Marlowe
Level 10
Level 10
First like given 50 questions asked 10 questions asked

Set the IMO to 18MHz.

   

A tip: set UART to byte mode.

   

 

   

Bob

0 Likes
Anonymous
Not applicable

Hi Bob,

   

That removed the warning. Thanks!

   

Best Regards,

   

Sharan

0 Likes
Bob_Marlowe
Level 10
Level 10
First like given 50 questions asked 10 questions asked

I forgot to explain why.

   

Your main clock was set to 12MHz. To derive the needed UART clock it had to be divided. Because this is like an integer division there was some remainder which was too large to tolerate. If it does not get in conflict with other given guidelines as power consumption etc. I would suggest to use the IMO at its highest frequency the chip allows for.

   

 

   

Bob

Anonymous
Not applicable

Bob,

   

How do you change the clock? and What is IMO? I am using the CYBLE-022001-00

0 Likes
Bob_Marlowe
Level 10
Level 10
First like given 50 questions asked 10 questions asked

Use Creator 4.0. In Workspace Explorer (left hand side) you see an entry for the clocks.

   

IMO is the "Internal Main Oscillator" which is used as source for all the internal clocks you need.

   

Under the "Datasheets" tab you find descriptions of all the resources you are using, search for description of elements/names you are not familiar with (yet).

   

 

   

Bob

0 Likes
Anonymous
Not applicable

This projet works with PRoC Creator 3 but not version 4

   

I cannot program my board from The Creator 4.0 IDE. It will not recognize my device. These are my erroes

   

--------------- Build Started: 12/12/2016 09:02:25 Project: UART_to_BLE_peripheral, Configuration: ARM GCC 4.9-2015-q1-update Debug ---------------
The code generation step is up to date.
The compile step is up to date, no work needs to be done.
The link step is up to date, no work needs to be done.
--------------- Build Succeeded: 12/12/2016 09:02:25 ---------------
Warning: dbg.M0039: There was an error running port acquire: Can not acquire SWD device!
Warning: dbg.M0039: There was an error running port acquire: Port has not been opened
Warning: dbg.M0039: There was an error running port acquire: Port has not been opened

   

using this project

   

https://github.com/cypresssemiconductorco/EZ-BLE_PRoC_Module/tree/master/Example_projects/UART_to_BL...

   

I had to update the BLE component to get it to compile/build

0 Likes
Bob_Marlowe
Level 10
Level 10
First like given 50 questions asked 10 questions asked

Please post your complete project, so that we all can have a look at all of your settings. To do so, use
Creator->File->Create Workspace Bundle (minimal)
and attach the resulting file.

   

 

   

Bob

0 Likes
lock attach
Attachments are accessible only for community members.
Anonymous
Not applicable

Her is the project

0 Likes
Bob_Marlowe
Level 10
Level 10
First like given 50 questions asked 10 questions asked

I cannot see which of the Cypress boards / kits and what programming equipment you are using. The UART buffers seem a bit high as the baud rate, was this in the original project?

   

 

   

Bob

0 Likes