Maximum Calculator (`max_calculator_xs`)

Streams incoming I/Q data from the input port to the output port and makes the maximum I and maximum Q values available for reading via properties.

Design

I/Q data is continuously read from the input port and written to the output port.

All I/Q values in the input data are compared against maximum I/Q values stored in properties within the worker. If the I/Q values in the input exceed the current I/Q maximum values then the maximum values are updated with the new input values. The flags indicating the maximum value is valid are set true if a sample has been received since the last reset.

When the maximum I/Q value is read from the component, it sets the property to the minimum value that can be represented by a signed 16 bit integer, -32768, and the associated valid property is set to false to indicate no maximum value exists.

Interface

<?xml version="1.0"?>
<componentspec>
  <!-- The max_i_is_valid/max_q_is_valid properties are *intentionally* placed
       above max_i/max_q in this XML file to ensure that they are read before
       the reset behavior caused by max_i/max_q property reads. -->
  <property name="max_i_is_valid" type="bool" volatile="true" description="Indicates ``max_i`` is valid."/>
  <property name="max_q_is_valid" type="bool" volatile="true" description="Indicates ``max_q`` is valid."/>
  <property name="max_i" type="short" volatile="true" description="Maximum I value observed on input port since last read."/>
  <property name="max_q" type="short" volatile="true" description="Maximum Q value observed on input port since last read."/>
  <port name="input" producer="false" protocol="complex_short_timed_sample-prot"/>
  <port name="output" producer="true" protocol="complex_short_timed_sample-prot"/>
</componentspec>

Opcode Handling

All opcodes are passed through this component without modification.

Properties

max_i_is_valid: Indicates max_i is valid.
- Type: bool
- Access:
  - Parameter: False
  - Writable: False
  - Initial: False
  - Volatile: True
- Default value: None
max_q_is_valid: Indicates max_q is valid.
- Type: bool
- Access:
  - Parameter: False
  - Writable: False
  - Initial: False
  - Volatile: True
- Default value: None
max_i: Maximum I value observed on input port since last read.
- Type: short
- Access:
  - Parameter: False
  - Writable: False
  - Initial: False
  - Volatile: True
- Default value: None
max_q: Maximum Q value observed on input port since last read.
- Type: short
- Access:
  - Parameter: False
  - Writable: False
  - Initial: False
  - Volatile: True
- Default value: None

Reading the max_i or max_q property will reset the value to the initial value of -32768 and clear the corresponding max_i_is_valid or max_q_is_valid property.

Ports

Inputs:

input: Primary input samples port.
- Protocol: complex_short_timed_sample-prot
- Optional: False

Outputs:

output: Primary output samples port.
- Protocol: complex_short_timed_sample-prot
- Optional: False

Implementations

max_calculator_xs (RCC)
max_calculator_xs (HDL)

Example Application

</application>
<application done="file_write">
  <instance component="ocpi.core.file_read" connect="max_calculator_xs">
    <property name="filename" value="input.bin"/>
  </instance>
  <instance component="ocpi.comp.sdr.instrument.max_calculator_xs" connect="file_write">
  </instance>
  <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

Limitations

Limitations of max_calculator_xs are: