MATLAB Function Block Design Patterns for HDL - MATLAB & Simulink (original) (raw)

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You can use MATLAB Function blocks to write algorithms for implementation in Simulink® and Stateflow®, then use this code for HDL code generation. You can use the HDL design patterns library eml_hdl_design_patterns to implement common hardware modeling algorithms using the MATLAB Function block. The library contains examples that demonstrate hardware-friendly applications of the MATLAB Function block for HDL code generation.

MATLAB Function block compatible functions

To open the library, at the MATLAB® command prompt, enter:

You can use the blocks in the library to model various hardware elements by:

When you create custom blocks, you can control whether to inline or instantiate the HDL code generated from MATLAB Function blocks. To inline or instantiate the HDL code, in the Configuration Parameters dialog box, click > . In the right pane, in the tab, select Inline MATLAB Function block code.

HDL Design Pattern Blocks

This table summarizes some of the categories of HDL design patterns in theeml_hdl_design_patterns library. For more information on the different blocks, see Create Hardware Design Patterns Using the MATLAB Function Block For HDL Code Generation.

Library Subsystem Purpose
Combinatorics Combinatorial fixed-point algorithms, such as expressions containing addition, subtraction, and multiplication operators with different fixed-point data types.
Adders Algorithms that model different adder logic.
Delays Algorithms to model integer delay, tap delay, and tap delay vector blocks by using vectors of persistent variables. Use these design patterns to implement sequential algorithms that carry state between executions of the MATLAB Function block in a model.
Comparators Algorithms for finding the minimum value of a vector.
FSMs MATLAB Function block control constructs such as switch/case andif-else, coupled with fixed point arithmetic operations to model control logic quickly.TheFSMs/mealy_fsm_blk andFSMs/moore_fsm_blk blocks provide example implementations of Mealy and Moore finite state machines in the MATLAB Function block.
Counters Counter logic that shows how to model state and quantize data elements within loops.
Shift Registers Algorithms that model shift register hardware elements.The shift_reg_1by32 block shows how to model shift registers by using thebitsliceget andbitconcat functions. This function implements a serial input and output shifters with a 32–bit fixed-point operand input.Theshift_reg_1by64 block shows a 64 bit shifter. In this case, the shifter uses two fixed-point words to represent the operand, overcoming the 32-bit word length limitation for fixed-point integers.
Word Twiddlers Algorithms that perform word conversions, such as conversions from an integer to bits and bits to an integer.

Using Blocks in this Library for HDL Code Generation

To build models using blocks in this library and generate HDL code:

For more information on generating HDL code from a MATLAB Function block, see Generate HDL Code from a MATLAB Function Block.

Fixed-Point Algorithm Support

The MATLAB Function block supports floating-point arithmetic and fixed-point arithmetic by using the Fixed-Point Designer™fi function. This function supports rounding and saturation modes that you can use to code algorithms that manipulate arbitrary word and fraction lengths. HDL Coder™ supports allfi rounding and overflow modes. HDL code generated from theMATLAB Function block is bit-true to MATLAB semantics. Generated code uses bit manipulation and bit access operators, such as slice, extend, reduce, and concatenate that are native to VHDL and Verilog. The eml_hdl_design_patterns library includes example blocks that use the fi object, such as the blocks in theAdders subsystem.

See Also

Check for MATLAB Function block settings