4.4.8 Propagating IRS Nets Outgoing from <Block1> to <Block2>

MSVT checks the separation of the IRS nets corresponding to a given block from external nets, per the specified separation criteria. If any of the nets of the design fail to satisfy separation criteria, then information related to the violating net is listed in the Propagating IRS nets outgoing from <block name> to <block name> section of the report and MSVT treats this as an error. This section is empty if your design does not have any net violating separation criteria.

MSVT Output Report

The following example shows that the IRS net block4_0_TX connecting block4_0and block1_0 instances is failing to meet separation criteria. This net can be observed by an external net block3_0/APB_dp_fp_1/U0/i_post_norm_mul/un3_s_ine_o_1_0_21_Z of block block3_0.

Propagating IRS nets outgoing from block4_0 to block1_0

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Propagating IRS nets outgoing from block4_0 to block1_0
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   Net block4_0_TX
      can be observed by cell block3_0/APB_dp_fp_1/U0/i_post_norm_mul/un3_s_ine_o_1_0_29
      through net block3_0/APB_dp_fp_1/U0/i_post_norm_mul/un3_s_ine_o_1_0_21_Z
      with cluster separation (13,0) due to 3 failing switches:
      When a routed Mux at (1269,93) fails
      The path is also driven by  constant '1'  signal
         Through an existing routed Buffer at (1269,93)
         Through an existing routed Buffer at (1197,93)
      When a routed Mux at (1137,93) fails
      The path is also driven by  constant '1'  signal
         Through an existing routed Buffer at (1137,93)
         Through an existing routed Buffer at (1065,93)
      When a routed Mux at (1000,93) fails
      The path is also driven by  block3_0/APB_dp_fp_1/U0/i_post_norm_mul/un3_s_ine_o_1_0_21_Z signal
         Through an existing routed Buffer at (1000,93)
         Through an existing routed Mux at (990,93)
         Through an existing routed Mux at (990,93)
         Through an existing routed Buffer at (990,93)
         Through an existing routed Mux at (990,93)
         Through an existing routed Mux at (990,93)
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The example report indicates that an IRS signal through the net block4_0_TX between blocks block4_0 and block1_0 is not separated by the number of required switches specified in the DESIGN_SEPARATION parameter from another net un3_s_ine_o_1_0_21_Z, which is a part of the block3_0 block.

If parameter REGIONS_VERBOSITY is set to ‘1’, then MSVT outputs the following additional information related to the floorplan. These sections provide additional information related to the design and cannot be considered as errors.