Extrema

ROHD-HCL provides a component to find the extrema of a list of Logic.

The component Extrema will determine an extrema (maximum or minimum) and their position in a list of Logics.

Description

Extrema will take in an input containing a List<Logic> along with a parameter max.

• max is a boolean indicating whether to find the maximum value (true), or the minimum value (false). Default is true.

Extrema will then ouput two Logic signals:

• index The index or position of the first extrema in the list.

  • index will be a Logic with the smallest width needed to represent the largest possible index in the list.

  • If multiple instances of the same extrema exists in the list, the index of the first instance will be returned.

• val The value of the extrema.

  • val will be a Logic with a width equal to the largest width of any element in the list.

The List<Logic> may contain Logics of any width. They will all be considered positive unsigned numbers.

Extrema will throw an exception if the Logic list is empty.

Example Usage

Dart code:

void main() {
  // Example list of Logic signals.
     final signals = [
      Logic(width: 8)..put(LogicValue.of([LogicValue.one, LogicValue.zero])), //0b10
      Logic(width: 4)..put(LogicValue.ofInt(13, 4)), //0xD
      Logic()..put(LogicValue.one), //0b1
      Logic(width: 8)..put(LogicValue.ofString('00001101')), // 0xD
      Logic(width: 4)..put(LogicValue.ofString('0001')), //0b1
    ];

    // Create an Extrema module to find the minimum value.
    final findMin = Extrema(signals, max: false);
    await findMin.build();
    // Create an Extrema module to find the first maximum value.
    final findMax = Extrema(signals);
    await findMax.build();

    // Assign the integer representation of the value of the index to a variable.
    final x = findMax.index.value.toInt();
    print('x equals findMax index: $x');

    // print the index and value of the minimum as values
    print('findMin index as a value: ${findMin.index.value}');
    print('findMin value as a value: ${findMin.val.value}');

    // print the index and value of the maximum as values
    print('findMax index as a value: ${findMax.index.value}');
    print('findMax val as a value: ${findMax.val.value}');
}

Console output:

x equals findMax index: 1
findMin index as a value: 3'h2
findMin value as a value: 8'h1
findMax index as a value: 3'h1
findMax val as a value: 8'hd