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Implement Sine and Cosine Block with Control Signals

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This example shows how to implement the control-signal based SinCos block and use it generate HDL code.

Open and Run Simulink Model

Specify the input data as a linear sweep through values in the range [-pi, pi]. You can change these values according to your requirements.

input_values = (-pi:.01/(2*pi):pi)';

Specify the word length for fixed-point datatypes and the latency for the model. The latency depends up on the number of iterations.

WL_SinCos = 18; latency_SinCos = 12;

Open the hdlcoder_sincos_control model and specify a stop time sufficient to process all the input combinations. The model has SinCos block that implements the SinCos using CORDIC algorithm. The other trigonometric function blocks, such as Sin, Cos, and Cos + jSin, use the same CORDIC approximation method.

stoptime_sincos = length(input_values)-1+latency_SinCos;
open_system('hdlcoder_sincos_control')
sim('hdlcoder_sincos_control')

This figure shows the waveform when you simulate the above model. The dataOut output is valid when validOut is 1.

Validate Simulink Output By Using Reference Output

To validate the output of the Simulink model, compare the this output with a reference value. To obtain the reference values, use the sin and cos function. Compute the reference value for Sine output by using the sin function.

comparison_plot_sincos(sin(input_values),sim_final_sintheta(valid_out),5,'sin');

Maximum Error sin 1.005291e-03

Compute the reference value for Cosine output by using the cos function. The maximum error value is significantly smaller than the output of the model.

comparison_plot_sincos(cos(input_values),sim_final_costheta(valid_out),6,'cos');

Maximum Error cos 1.036532e-03

Generate HDL Code for SinCos Implementation

Check the HDL settings of the model by using the hdlsaveparams function.

hdlsaveparams('hdlcoder_sincos_control')

%% Set Model 'hdlcoder_sincos_control' HDL parameters
hdlset_param('hdlcoder_sincos_control', 'HDLSubsystem', 'hdlcoder_sincos_control/SinCos');
hdlset_param('hdlcoder_sincos_control', 'ResetType', 'Synchronous');
hdlset_param('hdlcoder_sincos_control', 'SynthesisTool', 'Xilinx Vivado');
hdlset_param('hdlcoder_sincos_control', 'SynthesisToolChipFamily', 'Virtex7');
hdlset_param('hdlcoder_sincos_control', 'SynthesisToolDeviceName', 'xc7v2000t');
hdlset_param('hdlcoder_sincos_control', 'SynthesisToolPackageName', 'fhg1761');
hdlset_param('hdlcoder_sincos_control', 'SynthesisToolSpeedValue', '-2');
hdlset_param('hdlcoder_sincos_control', 'TargetDirectory', 'hdl_prj\hdlsrc');
hdlset_param('hdlcoder_sincos_control', 'TargetFrequency', 500);

hdlset_param('hdlcoder_sincos_control/SinCos/LumpLatency', 'Architecture', 'MATLAB Datapath');
% Set SubSystem HDL parameters
hdlset_param('hdlcoder_sincos_control/SinCos/LumpLatency', 'FlattenHierarchy', 'on');

hdlset_param('hdlcoder_sincos_control/SinCos/LumpLatency1', 'Architecture', 'MATLAB Datapath');
% Set SubSystem HDL parameters
hdlset_param('hdlcoder_sincos_control/SinCos/LumpLatency1', 'FlattenHierarchy', 'on');

hdlset_param('hdlcoder_sincos_control/SinCos/SinCos', 'Architecture', 'Cordic');

hdlset_param('hdlcoder_sincos_control/SinCos/ValidLine', 'Architecture', 'MATLAB Datapath');
% Set SubSystem HDL parameters
hdlset_param('hdlcoder_sincos_control/SinCos/ValidLine', 'FlattenHierarchy', 'on');

To generate HDL code for the SinCos block in the model, use the makehdl function.

makehdl('hdlcoder_sincos_control/SinCos')
close_system('hdlcoder_sincos_control')
close all;

### Working on the model <a href="matlab:open_system('hdlcoder_sincos_control')">hdlcoder_sincos_control</a>
### Generating HDL for <a href="matlab:open_system('hdlcoder_sincos_control/SinCos')">hdlcoder_sincos_control/SinCos</a>
### Using the config set for model <a href="matlab:configset.showParameterGroup('hdlcoder_sincos_control', { 'HDL Code Generation' } )">hdlcoder_sincos_control</a> for HDL code generation parameters.
### Running HDL checks on the model 'hdlcoder_sincos_control'.
### Begin compilation of the model 'hdlcoder_sincos_control'...
### Begin compilation of the model 'hdlcoder_sincos_control'...
### Working on the model 'hdlcoder_sincos_control'...
### Working on... <a href="matlab:configset.internal.open('hdlcoder_sincos_control', 'GenerateModel')">GenerateModel</a>
### Begin model generation 'gm_hdlcoder_sincos_control'...
### Rendering DUT with optimization related changes (IO, Area, Pipelining)...
### Model generation complete.
### Generated model saved at <a href="matlab:open_system('hdl_prj/hdlsrc/hdlcoder_sincos_control/gm_hdlcoder_sincos_control.slx')">hdl_prj/hdlsrc/hdlcoder_sincos_control/gm_hdlcoder_sincos_control.slx</a>
### Begin VHDL Code Generation for 'hdlcoder_sincos_control'.
### Working on hdlcoder_sincos_control/SinCos/SinCos as hdl_prj/hdlsrc/hdlcoder_sincos_control/SinCos_block.vhd.
### Working on hdlcoder_sincos_control/SinCos as hdl_prj/hdlsrc/hdlcoder_sincos_control/SinCos.vhd.
### Code Generation for 'hdlcoder_sincos_control' completed.
### Generating HTML files for code generation report at <a href="matlab:hdlcoder.report.openDdg('/tmp/Bdoc24a_2528353_2763154/tp0c1aecf4/hdlcoder-ex40921781/hdl_prj/hdlsrc/hdlcoder_sincos_control/html/hdlcoder_sincos_control_codegen_rpt.html')">hdlcoder_sincos_control_codegen_rpt.html</a>
### Creating HDL Code Generation Check Report file:///tmp/Bdoc24a_2528353_2763154/tp0c1aecf4/hdlcoder-ex40921781/hdl_prj/hdlsrc/hdlcoder_sincos_control/SinCos_report.html
### HDL check for 'hdlcoder_sincos_control' complete with 0 errors, 0 warnings, and 0 messages.
### HDL code generation complete.

SinCos Block Synthesis Performance

This figure shows the SinCos block synthesis performance on the Xilinx Virtex 7 and Intel Stratix V devices.