DataType Propagation

The SystemVerilog Netlister allows you to modify the dataType, portKind, and isUnpacked properties, which are specific to an instance.

The datatype can be propagated from the following:

• From text views
• From instance ports on the symbol (place master).
• From instance ports in the schematic

When ignoreDataType is set to t, the dataType, portKind, and isUnpacked properties are ignored. Instead, the dataType information that is propagated from the bottom-level cell to the top-level cell is considered.

You can add the ignoreDataType property on a specific instance terminal in the schematic. If this property is selected, the SystemVerilog Netlister will not print the Master Value and the Local Value.

Additionally, you can modify the local values of the dataType, portKind, and isUnpacked port properties that are associated with a specific instance of a cell.

The following table clearly describes the impact of enabling and disabling the ignoreDataType property on the port of an instance in different scenarios:

Condition	Additional Condition	Result
ignoreDataType = t		The master values and local values of dataType, portKind, and isUnpacked are ignored. Instead, dataType information propagated from the bottom cell to the top cell is used.
ignoreDataType = nil	The local value of dataType is set to custom_value.	The local value of the specific instance is used instead of the value set on the symbol cell.
ignoreDataType = nil	The local values are not set for dataType, portKind, and isUnpacked.	The master value of the symbol cell property is used.

Example

Consider the input port I2 in the following schematic and the related condition scenarios that follow.

• When ignoreDataType is set to t on the port of an instance
  When you set ignoreDataType to t on I2, the master and local values of dataType and portKind are ignored. In such a case, dataType information that is propagated from the bottom-level cell to the top-level cell is used.
  
  
  The following example shows how the netlist displays the port information in this scenario:

  module tb_w_voltage ( 
  output wire logic  VOUT0, 
  output wire logic  VOUT1, 
  output  wire logic  VOUT2, 
  input  wire logic  GNDA_ADC, 
  input  voltage         VIN0,
  input  voltage       VIN1 
  );

  Here, the wire logic value is derived from the dataType property of the bottom-level cell.
• When ignoreDataType is set to nil and the local value of dataType is set to custom_value
  When you set ignoreDataType to nil on I2 and the local value dataType to myvoltage, the local value myvoltage of the specific instance is used, instead of the master value voltage that is set on the symbol cell.
  
  
  The following example shows how the netlist displays the port information in this scenario:

  module tb_w_voltage ( 
  output wire logic      VOUT0, 
  output wire logic   VOUT1, 
  output wire logic   VOUT2, 
  input  myvoltage        GNDA_ADC,
  input  voltage      VIN0, 
  input  voltage      VIN1 
  );

  Here, the local value overrides the master value.
• When ignoreDataType is set to nil and the local value of dataType is not set
  When you set ignoreDataType to nil on I2 and the local values of dataType and portKind are not set, the master value voltage of the symbol cell property is used.
  
  
  The following example shows how the netlist displays the port information in this scenario:

  module tb_w_voltage ( 
  output wire logic   VOUT0, 
  output wire logic   VOUT1, 
  output wire logic   VOUT2, 
  input  voltage      GNDA_ADC,
  input  voltage      VIN0, 
  input  voltage      VIN1 
  );

  Here, the property of the symbol cell (master value) is used.

Related Topics

Launching SystemVerilog Netlister

SystemVerilog Netlister Graphical User Interface

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