Hierarchical Pin Creation using the Pin Tool

The Auto-Create Pins form includes the Hierarchical Depth option to enable hierarchical pin creation and pin promotion from lower levels to the top level. You can specify the start level from which the tool has to start hierarchical pin creation and promotion.

When the Hierarchical Depth option is selected, the tool follows an iterative approach by creating pins at the lower-most level, promoting them to the next higher level, and so on until it reaches the top level.

The following example shows the hierarchical pin creation and pin promotion in a design. The initial design has hierarchical cells in the following sequence:

Top Level > Level A > Level B > Level C

Each cell has a signal shape in layer M1 and drawing purpose overlapping each other. There is one shape in level B in layer M2 and one in level C in layer M2. Also, there is a pin shape in level B in layer M3.

When the Auto-Create Pins command is run with Multiple Top Layer selected and Hierarchical Depth set to 4, pins are created in the following sequence:

• Level C
  • No pin is created on the C-M1 shape because Multiple Top Layer is selected and M1 is not the top layer in cell C.
  • A pin is created on the C-M2 shape with purpose set to pin.
• Level B
  • No pin is created on the B-M1 shape because Multiple Top Layer is selected and M1 is not the top layer in cell B.
  • The C-M2 pin shape is promoted to level B and a pin shape is created on B-M2.
  • The B-M3 pin shape is retained.
• Level A
  • Pin shape A-M1 is created on the pin purpose because M1 is the top layer in cell A.
  • Pin shapes B-M2 and B-M3 are promoted to level A and pin shapes A-M3 and A-M2 are created.
  • All the pins are strongly connected.
• Top Level:
  • The M1 pin shape is promoted to the top level. All the promoted pin shapes are merged into a Top-M1 shape and converted to a pin shape.
  • The M2 and M3 pin shapes are promoted to the top level.
  • All the pins are strongly connected.
    
    

Related Topics

Auto-Create Pins Form

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