Friday, April 17, 2015

Hardware Co-simulation for Non Memory Mapped Ports using Simulink and System Generator

Hardware or FPGA is a primary requirement for any real time implementation of mathematical algorithms. The main drawback of the process is the limited resources and the interfaces available on the FPGA for the co-simulation process. One of the main highlighted concern is the mapping of the peripheral ports on the FPGA with the algorithm. 

Co-simulation is the best process to use for the real time implementation of the algorithms because the process facilitates the features of the two tools simultaneously. MATLAB is known as the best tool for the implementation of the mathematical algorithms for a number of applications. The other tool System Generator from by the Xilinx is known best for the hardware implementation of the algorithms. 

Both the tools work together simultaneously to real time implementation of the mathematical algorithms on the FPGAs. The complications are their when you want to use the LEDs, Buttons or other output devices. To resolve these problems we manually create the Non Memory Mapped Ports according to the steps given below.

To manually create NMM we need these different Simulink and system generator block sets.
1.       In1
2.       Convert
3.       Gateway In
4.       Out1
5.       Terminator

To generate the library subsystem we have to put these block as in the given fig:1

Fig: 1

The work is almost done we just need to run the given three command on the MATLAB command window after selecting the “Gateway Out” block

>>xlSetNonMemMap(gcbh, 'Xilinx', 'ethernetcosim'); 
>>xlSetPortParams(gcbh, 'IOConstraint', 'NET "pmod0" LOC = U18;');

This command is to map output of the design to the LED of the FPGA. “U18” is the pin location of the LED<0> in our case and can be changed on the basis of different pin location of the FPGAs.


This command is to confirm the pin mapping.

To use these blocks, right click after selecting all the blocks and make subsystem of them and put the subsystem wherever you want to use with any Simulink model. 

The block is now ready to use for the NMM.