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HPS DDR3 assigments

ABary
Beginner
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I have a prototype board that uses a DDR3 SDRAM connected to HPS in Cyclone V device.

The board has a error, bank pins BA[0] and BA[2] are swapped. Is it the way to re-swap this outputs ?

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a_x_h_75
New Contributor III
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Unfortunately not.

 

Does your design use both BA[0] & BA[2]? Are both wired up? Or are you intending to use a memory part which doesn't use BA[2]? Dare I suggest that, if they're both wired up and you fit a suitable memory device, it''l just work... Queue barrage of things I've failed to think of. However, having a quick look at the command truth table there aren't any commands that rely on the wiring of BA. So, selecting bank 0 instead of 2 and vice versa should simply result in data being written to and read from different banks in the memory device.

 

Cheers,

Alex

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ABary
Beginner
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Many thanks for replay. In PCB pin HPS_BA[0] from HPS is connected to pin DDR_BA[2] on DDR3 memory (2 chips of 256Mx16), pin HPS_BA[2] is connected to DDR_BA[0], pins for address bit [1] are connected correctly. This error was detected, because of DDR calibration failed during U-boot preloader start.

Datasheet of used memory devices shows that mode registers are selected by BA[1..0] just. I hope there is the way to swap this bits, maybe in u-boot sources, or, I know it's crazy, in HPS system verilog sources.

 

Regards,

Andrew

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a_x_h_75
New Contributor III
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I'm afraid you're stuck. They can be swapped - a restriction of the Hard Processor System you're using. Unfortunately, the I/O is hard wired as well.

 

Cheers,

Alex

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