Step 6: Implementing the First Configuration - 2022.1 English

Vivado Design Suite Tutorial: Dynamic Function eXchange (UG947)

Document ID
UG947
Release Date
2022-05-31
Version
2022.1 English

In this step, you place and route the design and prepare the static portion of the design for reuse with new Reconfigurable Modules.

Implementing the Design

  1. Optimize, place, and route the design by issuing the following commands:
    opt_design
    place_design
    route_design

    After both place_design and route_design, examine the state of the design in the Device view (see the following figure). One thing to note after place_design is the introduction of Partition Pins. These are the physical interface points between static and reconfigurable logic. They are anchor points within an interconnect tile through which each I/O of the Reconfigurable Module must route. They appear as white boxes in the placed design view. For pblock_shift, they appear in the top of that Pblock, as the connections to static are just outside the Pblock in that area of the device. For Pblock_count, they appear outside the user-defined region, as SNAPPING_MODE vertically collected more frames to be added to the Reconfigurable Partition.

    Figure 1. Partition Pins within Placed Design
  2. To find these partition pins in the GUI easily:
    1. Select the Reconfigurable Module (for example, inst_shift) in the Netlist pane.
    2. Select the Cell Pins tab in the Cell Properties pane.
  3. Select any pin to highlight it, or use Ctrl+A to select all. The Tcl equivalent of the latter is: select_objects [get_pins inst_shift/*]
  4. Use the Routing Resources toolbar button to toggle between abstracted and actual routing information, and to change the visibility of the routing resources themselves. All nets in the design are fully routed at this point.
Figure 2. Close up of First Configuration Routed

Saving the Results

  1. Save the full design checkpoint and create report files by issuing these commands:
    write_checkpoint -force Implement/Config_shift_right_count_up_implement/top_route_design.dcp
    report_utilization -file Implement/Config_shift_right_count_up_implement/top_utilization.rpt
    report_timing_summary -file Implement/Config_shift_right_count_up_implement/top_timing_summary.rpt
  2. [Optional] Save checkpoints for each of the Reconfigurable Modules by issuing these two commands:
    write_checkpoint -force -cell inst_shift Checkpoint/shift_right_route_design.dcp
    write_checkpoint -force -cell inst_count Checkpoint/count_up_route_design.dcp
    Tip: When running run_dfx.tcl to process the entire design in batch mode, design checkpoints, log files, and report files are created at each step of the flow.

    At this point, you have created a fully implemented Dynamic Function eXchange design from which you can generate full and partial bitstreams. The static portion of this configuration is used for all subsequent configurations. To isolate the static design, remove the current Reconfigurable Modules. Make sure routing resources are enabled, and zoom in to an interconnect tile with partition pins.

  3. Clear out Reconfigurable Module logic by issuing the following commands:
    update_design -cell inst_shift -black_box
    update_design -cell inst_count -black_box

    Issuing these commands results in many design changes as shown in the following figure:

    • The number of Fully Routed nets (green) decreased.
    • inst_shift and inst_count now appear in the Netlist view as empty.
    Figure 3. The inst_shift Module Before update_design -black_box
Figure 4. The inst_shift Module After update_design -black_box
  1. Issue the following command to lock down all placement and routing:
    lock_design -level routing

    Because no cell was identified in the lock_design command, the entire design in memory (currently consisting of the static design with black boxes) is affected. All routed nets now display as locked, as indicated by dashed lines in Figure 18. All placed components changed from blue to orange to show they are also locked.

  2. Issue the following command to write out the remaining static-only checkpoint:
    write_checkpoint -force Checkpoint/static_route_design.dcp

    This static-only checkpoint is used for future configurations.

  3. Close this design before moving on to the next configuration:
    close_project