Data Types and Scope

Supported Data Types

HDL Coder™ supports the following subset of MATLAB® data types.

TypesSupported Data TypesRestrictions
Integer

  • uint8, uint16, uint32, uint64

  • int8, int16, int32, int64

In Simulink®, MATLAB Function block ports must use numeric types sfix64 or ufix64 for 64-bit data.
Real

  • double

  • single

HDL code generated with double or single data types can be used for simulation, but is not synthesizable.
Characterchar 
Logical

logical

 
Fixed point

  • Scaled (binary point only) fixed-point numbers

  • Custom integers (zero binary point)

Fixed-point numbers with slope (not equal to 1.0) and bias (not equal to 0.0) are not supported.

Maximum word size for fixed-point numbers is 128 bits.

Vectors

  • unordered {N}

  • row {1, N}

  • column {N, 1}

The maximum number of vector elements allowed is 2^32.

Before a variable is subscripted, it must be fully defined.

Matrices

{N, M}

Matrices are supported in the body of the design algorithm, but are not supported as inputs to the top-level design function.

Do not use matrices in the testbench.

Structuresstruct

Arrays of structures are not supported.

For the FPGA Turnkey and IP Core Generation workflows, structures are supported in the body of the design algorithm, but are not supported as inputs to the top-level design function.

Enumerationsenumeration

Enumeration values must be monotonically increasing.

If your target language is Verilog®, all enumeration member names must be unique within the design.

Enumerations at the top-level DUT ports are not supported with the following workflows or verification methods:

  • IP Core Generation workflow

  • FPGA Turnkey workflow

  • FPGA-in-the-Loop

  • HDL Cosimulation

Unsupported Data Types

In the current release, the following data types are not supported:

  • Cell array

  • Inf

Scope for Variables

Global variables are not supported for HDL code generation.

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