README.md

Autogen Framework Model Interfaces

The Autogen framework gives 3 major file based interfaces for models: model.json, modelparameters.m, and sm_stop_verify.m and 1 major interface available as a struct in the Matlab workspace: mp.

model.json

model.json is a required configuration file shared between the Autogen Framework and the Autogen Tools. This covers both system-level properties as well as run-time tunable parameters for the model via registers.
model.json properties:

• system: An object to describe the overall system
  • target: Which hardware system is being targeted, the audiomini or audioblade
  • sampleClockFrequency: The sampling rate of the audio being processed
  • systemClockFrequency: Clock rate of the audio processing on the FPGA
  • processing: Data processing format, either channel based ("channel") or sample based ("sample")
  • audioIn: Object representing the data type of the audio input
    • wordLength: number of total bits in the data type
    • fractionLength: number of fractional bits in the fixed point number
    • signed: true if the data type is signed, false otherwise
    • numberOfChannels: number of channels in the audio to be processed
  • audioOut: Object reprenting the data type of the audio output (Note: Currently unused, only inputDataType is read)
    • wordLength: number of total bits in the data type
    • fractionLength: number of fractional bits in the fixed point number
    • signed: true if the data type is signed, false otherwise
    • numberOfChannels: number of channels in the audio to be processed
• devices: An array of objects representing devices. Simulation support is only for one device.
  • device object
    • name: Name of the Simulink model
    • registers: An array of objects representing run-time tunable parameters as registers
    • register object
      • dataType: object representing the data type of the register
        • fractionLength: number of fractional bits in the fixed point number
        • signed: true if the data type is signed, false otherwise
        • type: string representation of type ('boolean', 'string', 'int')
        • wordLength: number of total bits in the data type
      • defaultValue: default value to set the register to (should be 1 or 0 for boolean types)
      • name: name of the tunable parameter
      • registerNumber: offset in memory for the register (starts at 1 and must have registerNumber's defined between 1 and the highest value given)

Model Parameters

modelparameters.m is an optional model specific script that can define both properties to directly interface with Autogen or to be available to the Simulink Model. These model parameters are available via the mp struct.

Configurable Autogen model parameters:

• testFile: A path to an audio file for input to the simulation. The number of channels should match numberOfChannels defined in model.json
• nSamples: Number of samples of the test audio source to simulate after resampling
• sim_prompts: Flag to enable prompts during simulation
• sim_verify: Enables simulation verification with the user defined script verifySim

Verifying the Simulation

If sim_verify is set to 1, then the Autogen framework will attempt to run the user defined script verifySim post-simulation. Autogen makes the output data available via the following two fields on the mp struct:

• dataOut: m x n array where m is the number of channels and n is the number of samples containing the channel's audio data

The verifySim should have the same inputs and outputs as the example below:

function mp = verifySim(mp, test_signal)

%% Verify that the test data got encoded, passed through the model, and
% decoded correctly. 

figure(1)
subplot(2,1,1)
plot(testSignal.audio(:,1)); hold on
plot(mp.dataOut(1,:))
title(['Delay = ' num2str(mp.register{2}.value) '  Bypass = ' num2str(mp.register{1}.value) '  Decay = ' num2str(mp.register{3}.value)  '  Wet/Dry Mix = ' num2str(mp.register{4}.value)])

subplot(2,1,2)
plot(testSignal.audio(:,2)); hold on
plot(mp.dataOut(2,:))
title(['Delay = ' num2str(mp.register{2}.value) '  Bypass = ' num2str(mp.register{1}.value) '  Decay = ' num2str(mp.register{3}.value)  '  Wet/Dry Mix = ' num2str(mp.register{4}.value)])

end

mp: The model parameters struct

Notable fields on the mp struct, in addition to those described above:

• W_bits: number of total bits in the audio data
• F_bits: number of fractional bits in the audio data
• nChannels: number of channels in the audio
• signed: true if the audio data is signed, false otherwise
• Fs: Sampling rate of the audio data
• Ts: Sampling time of the audio data
• Ts_sim: Sample time expected during Simulation
• register: Cell array of registers
  • name: Name of tunable parameter
  • value: Value that the tunable parameter is set to
  • dataType: Matlab datatype of the tunable parameter
  • timeseries: timeseries object containing the register's value for use in simulation