Sample Control Bus

Wireless HDL Toolbox™ blocks use a nonvirtual bus data type, samplecontrol, for control signals associated with serial data. The bus contains three boolean signals indicating the validity of a sample and the boundaries of the frame. You can easily connect one block to another, because all Wireless HDL Toolbox blocks use this bus for input and output. To convert frames into a sample stream and a samplecontrol bus, use the Frame To Samples block. This block serializes fixed-size frames. If your frames vary in size, use the whdlFramesToSamples function to convert the frames to a data vector in MATLAB^®, and then import the data into Simulink^®.

Signal	Description	Data Type
start	true for the first sample in the frame	Boolean
end	true for the last sample in the frame	Boolean
valid	true for any valid sample	Boolean

Troubleshooting:

When you generate HDL code from a Simulink model that uses this bus, you may need to declare an instance of samplecontrol bus in the base workspace. If you encounter the error Cannot resolve variable 'samplecontrol' when you generate HDL code in Simulink, use the samplecontrolbus function to create an instance of the bus type. Then try generating HDL code again.

To avoid this issue, the Wireless HDL Toolbox model template includes this line in the InitFcn callback.

evalin('base','samplecontrolbus')

You can also call this command from the MATLAB command line.