Binary Data Flow Gate (`packet_gate_b`)

Passes input binary samples to output port when metadata detected on ‘input_start’ port and discards input samples when metadata detected on ‘input_close’ port.: metadata_id = 0 metadata_value = 0

Design

The `packet_gate_b` component has two input ports and one output port. It is designed to pass through binary data received on the ‘input_open’ port to the output port once a metadata opcode is detected on the ‘input_open’ port. Until a metadata message is received on this port, all incoming binary data is discarded. If the gate is in an open state, samples will continue to flow until a metadata message is received on the ‘input_close’ port. All data samples and opcode messages received on the ‘input_close’ port are discarded. Once a metadata message is received on this port, all data samples received on the ‘input_open’ port are discarded, however, all opcode messages except metada are allowed to pass. A block diagram representation of the component function is given in metadata_gate_b-diagram.

Skeleton alternative text. — Figure 224: Packet Gate Component Usage.

Interface

<?xml version="1.0"?>
<componentspec>
  <property name='gate_open' type='bool' default='false' writable='true'/>
  <port name="input_open" producer="false" protocol="bool_timed_sample-prot"/>
  <port name="input_close" producer="false" optional="true" protocol="bool_timed_sample-prot"/>
  <port name="output" producer="true" protocol="bool_timed_sample-prot"/>
</componentspec>

Opcode Handling

All opcodes except ‘metadata’ are passed from input_open port to output when they are received. Opcodes received on the input_close port are discarded.

Properties

gate_open
- Type: bool
- Access:
  - Parameter: False
  - Writable: True
  - Initial: False
  - Volatile: False
- Default value: false

Ports

Inputs:

input_open: Primary input samples port and header detect.
- Protocol: bool_timed_sample-prot
- Optional: False
input_close: Tail detect.
- Protocol: bool_timed_sample-prot
- Optional: True

Outputs:

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

Implementations

Example Application

<?xml version="1.0"?>
<application done="file_write">
  <instance component="ocpi.core.file_read" connect="splitter_b">
    <property name="filename" value="input.bin"/>
  </instance>
  <instance component="ocpi.comp.sdr.interface.splitter"/>
  <instance component="ocpi.comp.sdr.communication.pattern_detector_b"
            name="start_pattern" connect="packet_gate_b" from="output" to="input_open">
    <property name="pattern" value="0x55555555faceface"/>
    <property name="bitmask" value="0x7fffffffffffffff"/>
  </instance>
  <instance component="ocpi.comp.sdr.communication.pattern_detector_b"
            name="stop_pattern" connect="packet_gate_b" from="output"
            to="input_close">
    <property name="pattern" value="0x5efacefa55555555"/>
    <property name="bitmask" value="0x7fffffffffffffff"/>
  </instance>
  <connection>
    <port instance="splitter" name="output_1"/>
    <port instance="start_pattern" name="input"/>
  </connection>
  <connection>
    <port instance="splitter" name="output_2"/>
    <port instance="stop_pattern" name="input"/>
  </connection>
  <instance component="ocpi.comp.sdr.communication.packet_gate_b" 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

Limitations

Limitations of metadata_gate_b are:

Must be used with components that generate metadata opcodes to trigger an ‘open’ or ‘close’ gate event. For example, pattern_detector_b.

Testing

Tested platforms: None

Binary Data Flow Gate (packet_gate_b)