Stream from FPGA to Processor Template

Use the Stream from FPGA to Processor template to create an SoC Blockset™ model for designing a datapath from hardware (FPGA) to software (Processor). To create a project using the "Stream to Processor" template, follow the steps to Create SoC Model Using SoC Blockset Template.

Top model of FPGA to Processor Template

Required Products

For sample-based processing, no additional products are required.

For frame-based processing, DSP System Toolbox™ is required.

Template Structure

This template models a counter as the test data source and minimal logic for the FPGA and processor algorithms. Use this template as a guide and replace the FPGA algorithm and Processor algorithm with your own functionality. The FPGA algorithm is a simple multiplication performed on input data from the test source and from a configReg parameter. The processor writes the configReg. This parameter is modeled using the Register Channel block. Data from the FPGA algorithm is passed to the processor through a Memory Channel block. The memory Channel Type parameter is set to AXI4-Stream to Software via DMA, which models the DMA data transfer through shared external memory.

The processor reads the computed data from the memory and performs additional computing, which is implemented in the template as a pass-through wire. You can view the simulation results by double-clicking the Vector Scope block in the testbench sink.

Modify Project

Modify the FPGA Model

In the MATLAB^® toolstrip, on the Project Shortcuts tab, click Open FPGA sample model to open the FPGA model. In the model, two areas are highlighted green, which represents user code: one in the FPGA Algorithm Wrapper block and one in the Test Source Wrapper block.

FPGA Algorithm Wrapper – Double-click to open the model. The algorithm wrapper contains a green-highlighted subsystem named FPGA Algorithm. This block has two inputs and one output and is implemented as a multiplier. Replace this block with your own FPGA algorithm. Add inputs and outputs as required.
Test Source Wrapper – This block includes a test source and is intended to generate stimulus as an input to the FPGA algorithm. This block is implemented as a counter in this template. Modify the test source to your needs, or replace it with an alternative source block.

Tip

When your FPGA model includes more than one IP, you must define each IP as a subsystem and connect the subsystems using a Stream Connector or Video Stream Connector block. For additional information, see Considerations for Multiple IPs in FPGA Model.

To enable consistent simulation behavior, click Open FPGA frame model in the Project Shortcuts tab and repeat this step. To simulate frame-based processing, you must have a DSP System Toolbox license.

Modify the Processor Model

In the MATLAB toolstrip, on the Project Shortcuts tab, click Open Processor model. The processor wrapper contains a blue highlighted subsystem representing the user code for the processor algorithm. Open the Processor Algorithm wrapper and replace the Processor Algorithm block with your desired algorithm.

Modify the Register Channel

The top model of a template also includes a register channel to communicate between the processor and the FPGA model. Use the register channel to configure the FPGA model, or to read and check status registers. The Register Channel block in the template includes one register. To add additional registers you must modify the register channel block parameters, the FPGA algorithm, and the processor algorithm:

Add registers to the register channel – Double-click the Register Channel block to open the block mask and add additional registers as needed. Adding registers creates additional ports on the Register Channel block. For additional information, see Register Channel.
Add ports to the processor model – Navigate to the Processor Algorithm Wrapper model. To navigate to the processor model, click Open Processor model on the Project Shortcuts tab. Double-click Processor Algorithm Wrapper to modify it.
For write registers, add an output port to the module and add logic to drive a value to the added output port. For read registers, add an input port and logic to process the information returned from a read register. From the top model, wire the port to the Register Channel block.
Add ports to the FPGA model – Navigate to the FPGA Algorithm Wrapper model. To navigate to the FPGA/Frame based processing model, click Open FPGA sample model on the Project Shortcuts tab. Double-click FPGA Algorithm Wrapper to modify it.
For write registers, add an input port to the module and logic to process the information returned from a read register. For read registers, add an output port and logic to drive a value to the added output port.
For equivalent behavior when using a Simulink^® sample-based variant, repeat this step for the sample-based processing model in the FPGA wrapper.
From the top model, wire the new port to the Register Channel block.