Control reg being removed from cyfitter.h

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jofic_334026
Level 3
Level 3
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I'm using the control regsister "DmaMsbReg" as the destination of a DMA transfer.  My custom component (MyOverlay) uses the value of this register on lines 251, 253 and 255 of MyOverlay.v.  However, the register is being removed from cyfitter.h.  Why?  It appears in cyfitter.h as the following:

   

/* DmaMsbReg */

   

#define DmaMsbReg_Sync_ctrl_reg__REMOVED 1u

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ETRO_SSN583
Level 9
Level 9
250 likes received 100 sign-ins 5 likes given

I turned off optimization to see what results would occur, design blew up

   

on me, eg. would not fit resources. Unless someone else can see issue consider

   

posting a CASE -

   

 

   

To create a technical or issue case at Cypress -

   

 

   

www.cypress.com

   

“Support”

   

“Technical Support”

   

“Create a Case”

   

 

   

You have to be registered on Cypress web site first.

   

 

   

Regards, Dana.

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

Too bad, but Creator is right.

   

You defined in verilog

   

    reg [1:0] byte_counter;     // Keeps track of current color byte (Y or Cr or Cb).

   


and later you question

   

            else if( byte_counter == 5 )  // Y(3)
                color = DmaMSB[3:0];

   


Since this could never ever be, it was optimized out, leaving no reference to DmaMSB in the file which allows for optimizing out the whole register.

   

 

   

Happy coding

   

Bob

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