The Optimize MATLAB Loops documentation page mentions that one can partially stream a loop using HDL Coder. How can I do this?
MATLAB: Using HDL Coder, how can I do partial streaming of a MATLAB loop
HDL Coderpartialpartiallystreamstreaming
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Besides the points mentioned on the documentation page, nested loops are only supported for streaming when the loop body resides in the nested loop alone, i.e. loop over rows in outer loop and columns in inner loop for some element-wise operations on a matrix.
If the loop body almost solely lives in the outer loop, it cannot be streamed as it is. In this case, in order to do loop streaming on the outer loop, this nested loop could be unrolled. This can be done by using a second loopspec pragma and specifying 'unroll' in it at the nested loop:
coder.hdl.loopspec('stream')for i = 1:N%...
coder.hdl.loopspec('unroll') for j = 1:M %... end%...endAs of MATLAB R2019a, HDL Coder only supports one Slave (input) AXI4-Stream interface, and one Master (output) AXI4-Stream interface per IP core. For many SDR and video applications, multiple input or output channels are needed.
At this time, a possible workaround is as follows:
1) In HDL Workflow Advisor Task 1.1, it is necessary to select a specific board for "Target platform" (e.g. "Zedboard"). If you select "Generic Xilinx Platform", it is not currently possible to support this workflow
2) Create and register a custom reference design for the selected board, following the workflow outlined here:
To ease this process, you can refer to an existing reference design for the selected board. For example, on a Windows machine the AXI4-Stream reference design for the Zedboard could be found at:
C:\ProgramData\MATLAB\SupportPackages\R2019a\toolbox\hdlcoder\supportpackages\zynq7000\+ZedBoard\+vivado_stream_2018_2This will also require exporting a block design from Vivado. A full example of this workflow can be found here:
3) In the custom reference design file (e.g. "plugin_rd.m"), call the "addAXI4StreamInterface" function multiple times to define multiple AXI4-Stream interfaces. Each one of these can be specified with a different Interface ID to distinguish them. For example, you might do the following in your custom reference design file:
% add first AXI4-Stream interface
hRD.addAXI4StreamInterface( ...'MasterChannelNumber', 1, ...'SlaveChannelNumber', 1, ...'MasterChannelConnection', 'axi_dma_s2mm/S_AXIS_S2MM', ...'SlaveChannelConnection', 'axi_dma_mm2s/M_AXIS_MM2S', ...'MasterChannelDataWidth', 32, ...'SlaveChannelDataWidth', 32, ...'InterfaceID', 'AXI4-Stream_1');% add second AXI4-Stream interface
hRD.addAXI4StreamInterface( ...'MasterChannelNumber', 1, ...'SlaveChannelNumber', 1, ...'MasterChannelConnection', 'axi_dma_s2mm_2/S_AXIS_S2MM', ...'SlaveChannelConnection', 'axi_dma_mm2s_2/M_AXIS_MM2S', ...'MasterChannelDataWidth', 32, ...'SlaveChannelDataWidth', 32, ...'InterfaceID', 'AXI4-Stream_2');4) Once this custom reference design is created, you can select it in HDL Workflow Advisor Task 1.2.
5) In HDL Workflow Advisor Task 1.3, you can now select from multiple AXI4-Stream interfaces. Note that due to the current limitations, it will be necessary to model and map the READY signals for all the AXI4-Stream interfaces.
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