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Visitor richards
Visitor
3,404 Views
Registered: ‎12-07-2007

Microblaze with SDRAM fails when embedded in ISE project. It works under EDK.

Hello All,

 

I have a simple microblaze project running under EDK 9.2.  When I embed a clone of the project into an otherwise-empty ISE top level project the SDRAM test fails.  Sometimes the synthesiser drops the maximum clock frequency from 60+ MHz in EDK to about 40MHz in ISE.

 

The fpga an xc3S1500-4.

The 'blaze is to run at 50MHz.

The Micron  MT48LC16M16A2-75 SDRAM is on an MPMC 3.00.b running at 100MHz.  The mpmc is connected to ixcl, dxcl (with 2k cache on each) and PLB4.6.

The 'blaze also has hardware debug, a uartlite and2 gpios. 

 

I expect I need to be a bit more clever than simply copying over the system clock frequency constraint to the ISE .ucf.  Can anyone give me some guidance?

 

Or am I going to have to bite the bullet and convert all my IP into EDK peripherals?

 

Richard

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2 Replies
Historian
Historian
3,402 Views
Registered: ‎02-25-2008

Re: Microblaze with SDRAM fails when embedded in ISE project. It works under EDK.


richards wrote:

Hello All,

 

I have a simple microblaze project running under EDK 9.2.  When I embed a clone of the project into an otherwise-empty ISE top level project the SDRAM test fails.  Sometimes the synthesiser drops the maximum clock frequency from 60+ MHz in EDK to about 40MHz in ISE.

 

The fpga an xc3S1500-4.

The 'blaze is to run at 50MHz.

The Micron  MT48LC16M16A2-75 SDRAM is on an MPMC 3.00.b running at 100MHz.  The mpmc is connected to ixcl, dxcl (with 2k cache on each) and PLB4.6.

The 'blaze also has hardware debug, a uartlite and2 gpios. 

 

I expect I need to be a bit more clever than simply copying over the system clock frequency constraint to the ISE .ucf.  Can anyone give me some guidance?

 

Or am I going to have to bite the bullet and convert all my IP into EDK peripherals?

 

Richard


Check your XMP to make sure that the parameter for InsertNoPads: is 1, not 0.

 

You need to make sure that ISE can find your constraint file, so add it as a source in your ISE project. That should include all of the necessary MPMC constraints as well as your clock and pinout constraints.

 

-a

----------------------------Yes, I do this for a living.
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Visitor richards
Visitor
3,379 Views
Registered: ‎12-07-2007

Re: Microblaze with SDRAM fails when embedded in ISE project. It works under EDK.

Thank you, Basman.

 

I the .xmp has InsertNoPads: 1.

 

The XMP-top-level project has no constraints other than the PERIOD on the 50MHz system clock.  This was transferred to the ISE project.  (The pin constraints are identical between the XMP and ISE .ucf files.)

 

 

Can you give me any hints on the sorts of constraints needed for the SDRAM?

 

Richard

 

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