Negator (negator_l)

Multiplies input values by \(-1\).

Design

Multiplies input values by \(-1\), to change the sign of the values.

The mathematical representation of the implementation is given in (111).

(111)\[y[n] = -x[n]\]

In (111):

• \(x[n]\) is the input values.

• \(y[n]\) is the output values.

A block diagram representation of the implementation is given in Figure 150:.

Figure 150: Negator implementation.

Interface

<?xml version="1.0"?>
<componentspec>
  <port name="input" producer="false" protocol="long_timed_sample-prot"/>
  <port name="output" producer="true" protocol="long_timed_sample-prot"/>
</componentspec>

Ports

Inputs:

• input: Primary input samples port.

  • Protocol: long_timed_sample-prot

  • Optional: False

Outputs:

• output: Primary output samples port.

  • Protocol: long_timed_sample-prot

  • Optional: False

Opcode Handling

Only values in a sample opcode message are multiplied by \(-1\). All other opcodes messages received are passed through this component without any effect.

Properties

None.

Implementations

• negator_l (HDL)

• negator_l (RCC)

Example Application

<?xml version="1.0"?>
<application done="file_write">
  <instance component="ocpi.core.file_read" connect="negator_l">
    <property name="filename" value="input.bin"/>
  </instance>
  <instance component="ocpi.comp.sdr.math.negator_l" connect="file_write"/>
  <instance component="ocpi.core.file_write">
    <property name="filename" value="output.bin"/>
  </instance>
</application>

Dependencies

The dependencies to other elements in OpenCPI are:

• None

There is also a dependency on:

• ieee.std_logic_1164

• ieee.numeric_std

Limitations

Limitations of negator_l are:

• The negation does not handle overflows caused by a full scale negative values being negated

Testing

Tested platforms: None

Component testing not completed.