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Swapping DDR3 pins to FPGA

aminpix

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I am trying to connect a two DDR3 to a Zynq FPGA. I need to swap some pins for DDR constrain purpose.
I had swap some data pins with some DDR_DMx pins as shown in the pictures.
DDR_DQxx are data pins and DDR_DMx are connected to DM pins.

The following pin connections are good or not?



1717015857922.png



1717015908535.png
 
Yes, to rout the data signals and make them same length, sometimes we need to swap the pins. I am not sure if I can swap DDR_DMx pins with DDR_DQxx or data pins or not?
 
@aminpix
I would never ever play around with dedicated DDR* pins. Please stick to dedicated pins if you wish the DDR* interface to operate correctly.
 
I know we can swap DDR_DQxx pins as long as they belong to the same byte group. For example we can swap DDR_DQ06 and DDR_DQ07 because they belong to the same byte group (DDR_DQ00 to DDR_DQ07). But we can not swap DDR_DQ06 and DDR_DQ09.

We usually swap these pins to make PCB routing easier or even make it possible.
I am not sure if we can swap DDR_DQxx with DDR_DQM0 or not?
 
You are right when you say you can swap DDR_DQxx inside the same group, but you cannot swap any of DDR_DMxx pins (with DDR_DQxx or other DDR_DMxx).
 
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