Negator (negator_s)

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 (76).

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

In (76):

• \(x[n]\) is the input values.

• \(y[n]\) is the output values.

A block diagram representation of the implementation is given in Figure 65:.

Figure 65: Negator implementation.

Interface

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

Ports

Inputs:

• input: Primary input samples port.

  • Protocol: short_timed_sample-prot

  • Optional: False

Outputs:

• output: Primary output samples port.

  • Protocol: short_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.

Parameters

Implementations

• negator_s (HDL)

• negator_s (RCC)

Example application

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

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

Testing

Component testing not completed.