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Hard macros power routing issues

dbekiaris

Hello everybody,

 I import a design in SoC Encounter 7.1, where three hard macros (SRAMs) exist. The problem is that when I am trying to create the power stripes and connect them with the core rings to synthesize the power grid, the SRAM p/g pins cannot connect with the remaining power/ground network, although I have selected the proper metal layer from the .lef files of the macros. Is there anything possible to do for this? I tried also to align pins of the specified macros with the power/ground stripes, but it failed again. If it is possible, please help. Thank you very much in advance.

 

  • Hi Kari,

    Thanks for answering and for the support. However, the problem is much more serious that I could imagine, except if I make wrong steps. The opens are shown at the left side of the macro boxes. So, as far as the rings cannot connect to the pins at these areas, the VDD/VSS pins stay unconnected. Therefore, I suppose the pin assignment of the macro blocks should change. Is this possible in SoC Encounter ? Can I create a partition and reassign the pins to the left top or to the bottom of the macro? Or the problem is not that ? Anyway, if you have any answer of idea on these questions, please help. Thank you very very much again in advance.

     Kind Regards

     

  •  You still haven't said how you're trying to connect the macro pins to the ring. Are you using the GUI? An sroute command? Just creating a ring around the macro isn't going to automatically connect the macro pins to the ring. I'm worried that some steps are being left out here. Have you reviewed the "Power Planning and Routing" chapter in the User Guide?

  • few clarifications needed...

    The core ring is not visible. could u provide zoomed view of pins on macro. what is the top metal layer of your design and in which layer do u have pins on macros.

    If i were to do powerplan for this and there is no specific requirements given.....

    1) i would make a core ring in M5/M6 bypassing all the macros.

    2) Make separate rings for each macro M5/M6 ( block rings not attached to core ring).

    3) make io wire connections from io pads to core ring and to block rings.

    4) make connection of macro pins to the block ring. ( depending on how the pins are on the macro).

    5) now adding stripes limiting them only to core ring. 

    6) here iam providing power to block ring directly from ios.and providing connections to macro only from block ring and iam completely excluding core ring and M5 stripes to Macros.

    try this if u like and let me know any issues in doing so........

     

    Thanks

    suraj 

  • Hello everybody and thanks again for answering Actually, everything I have done up until now is through the GUI. So, I create the core ring (following the .lef dimensions) on M6/M5 and then, I create block rings of M6/M5 for each of the macros, and then I try to do the special route only for the macro blocks. The result shows always unconnected pins, even if I try the "Connect corners of pin rings" option in the 'Sroute' window. I suppose the block rings are not on the corners, but on the left and the right side of the macro blocks, that's why they seem to be unconnected. The question is that if happens so, how can I connect them ? It would be difficult to do all this manually, as there are about 15 macros on the design. Thank you very much.

  •  Can you post a picture of the gui form when you try to do the sroute for the blocks? I'd like to see which options you're picking. You could also paste the resulting command from the log file. Again, I encourage you to try connecting one of the macro pins to its ring by hand, just to make sure it can be done without violations.

    Thanks!

    - Kari

  • Hello kari I post a picture from the block ring I try to connect to, through the Add Stripes wizard. I suppose that the problem is with the macro block, because the stripes are on the same metal layer with the power/ground of the macro. However, they can not be connected, even if I try other options (ommit stripes over block rings and omit stripes over selected blocks/fences/domains). Can you extract anything from this picture ? Please advise! Thank you very much in advance. Kind regards

  •  Can you zoom in more closely to the corner of that macro, so that I can see the macro corner, one or two of your stripes, the ring around the macro, and the macro pins? It is still difficult to tell what you're trying to do. It also still sounds like you're expecting addStripe to connect your block pins, which is not the use model. You will need to use Sroute to connect block pins outward to a stripe or ring.

     

  • I have seen the similar issue, then I debug this way:   I generate a hardmarco with  IO row, power ring and stripe,  

    when I do Sroute for the hardmarco, I createPGpin VDD and VSSI set extend POWER pin to the boundary, then I generate  LEF by lefOut -PGlayer 1,2 

       I debug the LEF, it show VDD and VSS as POWER pin,

       then I load the top level, I see exactly the problem you show here, top level cannot hook up the stripe and ring, there are open on blockwire and follow pin

     

     

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