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Visitor hafezmg48
Visitor
8,331 Views
Registered: ‎07-16-2014

Increasing RS232 baud rate gives me just zeros

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hello everyone,

 

intro:

 

I work with atlys board. using Microblaze processor. Using xilinx EDK and SDK as tools.

 

For an image processing purpose, I designed a custom coprocessor with FSL bus, which gets a (4,4) pixel window of an image from microblaze and applies a filter on it ,then sends it back to microblaze.I iterate the window on image to apply filter on all of the image.

 

I put the original image as a header file in C code. And use RS232 to send the resulted image from board to computer. The resulted image is a matrix of numbers between 0 and 255

 

First I used RS232 with baud rate 9600. it worked perfect and gives the resulted image to computer. the only problem was that the speed of sending image was too low. 

 

problem:

I went back to edk, changed RS232 baud rate to 19200 and regenerated everything. it also worked with 19200. but still the speed was too low.

 

I changed the baud rate to 57600 and regenerated everything. when I tested the design, IT GIVES THE ALPHABET CODES CORRECT BUT THE MATRIX IS ALL ZEROS.

 

for example main part of my C code is like:

 

xil_printf("hello");
print("Hello World\n\r");
MYCORE_SelfTest();       //the custom IP works here

 

xil_printf("printing final image...\r\n\r\n");
for(i=0;i<img_size;i++){
for(j=0;j<img_size;j++){
sprintf(out,"%d ",image_res[i][j]);
print(out);
}
print("\n\r");
}

 

 

 

and it gives me:

 

helloHello World
printing final image...

0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 

 

 

it's completely ridiculous! I don't know what is the relation between baudrate of RS232 and work of the FSL coprocessor.

If the problem is with baud rate, why the words are correct and just numbers are zero. if the problem is related to FSL coprocessor, why it works for slower baud rates!!!

 

please please help me!!

Do not go gentle into that goodnight. Rage, Rage, against the dying of the light!
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1 Solution

Accepted Solutions
Visitor hafezmg48
Visitor
14,841 Views
Registered: ‎07-16-2014

Re: Increasing RS232 baud rate gives me just zeros

Jump to solution

Found it myself,

 

it is a bug in EDK. I didn't get why but, possibly it doesn't perform required changes when you change the baude rate through the system assembly view. For a safe and confident change in baude rate you must start a new project and set the baud rate at the first of project wizard.

Do not go gentle into that goodnight. Rage, Rage, against the dying of the light!
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2 Replies
Visitor hafezmg48
Visitor
8,323 Views
Registered: ‎07-16-2014

Re: Increasing RS232 baud rate gives me just zeros

Jump to solution

My further tests(commenting the filter part and sending orginal image to RS232) has turned out that when baud rate is high the FSL core just sends zeros!! SO RIDICULOUS!!

somebody help me!

Do not go gentle into that goodnight. Rage, Rage, against the dying of the light!
0 Kudos
Visitor hafezmg48
Visitor
14,842 Views
Registered: ‎07-16-2014

Re: Increasing RS232 baud rate gives me just zeros

Jump to solution

Found it myself,

 

it is a bug in EDK. I didn't get why but, possibly it doesn't perform required changes when you change the baude rate through the system assembly view. For a safe and confident change in baude rate you must start a new project and set the baud rate at the first of project wizard.

Do not go gentle into that goodnight. Rage, Rage, against the dying of the light!
0 Kudos