Mux

Combine input signals of same data type and complexity into virtual vector

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Libraries:
Simulink / Commonly Used Blocks
Simulink / Signal Routing
HDL Coder / Commonly Used Blocks
HDL Coder / Signal Routing

Description

The Mux block combines inputs with the same data type and complexity into a virtual vector. You can use multiple Mux blocks to create a mux signal in stages, but the result is flat as if you used a single Mux block.

Ideally, use Mux blocks to group only function-call signals.

While a Mux block can create a virtual vector from signals that have the same data type and complexity, other blocks group signals in ways that provide more flexibility and efficiency.

• To group signals or messages, use a Bus Creator block instead of a Mux block. The Bus Creator block creates virtual buses, which give you the flexibility to group elements of different data types and complexity. Virtual buses also let you access elements by name instead of by index. If a block requires a virtual vector instead of a virtual bus, model compilation converts the bus to a vector.

• To concatenate input signals, use a Vector Concatenate block instead of a Mux block. The Vector Concatenate block creates a nonvirtual vector, which improves the efficiency of generated code.

For a comparison of mux signals, virtual buses, and concatenated signals, see Explore Composite Interfaces.

Examples

Function-Call Subsystems with Multiple Initiators

A function-call subsystem that is called by multiple different function-call initiators that are grouped by a Mux block.

• Open Model

Ports

Input

Port_1 — Input signal to include in mux signal

scalar | vector

Input signal to include in the mux signal, specified as a scalar or vector.

The input signals for a Mux block can be any combination of scalars and vectors, but they must have the same data type and complexity or be function-call signals.

Data Types: single | double | half | int8 | int16 | int32 | int64 | uint8 | uint16 | uint32 | uint64 | Boolean | fixed point | enumerated | image
Complex Number Support: Yes

Output

Port_1 — Output mux signal

vector

Output mux signal composed of the combined input signals, returned as a vector.

The elements of the output mux signal take their order from the port order of the input signals. For a description of the port order for various block orientations, see Identify Port Location on Rotated or Flipped Block.

Data Types: single | double | half | int8 | int16 | int32 | int64 | uint8 | uint16 | uint32 | uint64 | Boolean | fixed point | enumerated | image

Parameters

Number of inputs — Number of input signals

2 (default) | scalar | vector | cell array | comma-separated list of signal names

The number of input signals, specified as a scalar, vector, cell array, or comma-separated list of signal names. Some of these formats allow you to specify the signal names and sizes, as described in this table.

Format	Block Behavior
Scalar	The number of inputs to the Mux block. When you use this format, the block accepts scalar or vector signals of any size. The software assigns each input the name signalN, where N is the input port number.
Vector	The length of the vector specifies the number of inputs. Each element specifies the size of the corresponding input. A positive value specifies that the corresponding port can accept only vectors of that size. For example, [2 3] specifies two input ports of sizes 2 and 3, respectively. If an input signal width does not match the expected width, an error message appears. A value of -1 specifies that the corresponding port can accept scalars or vectors of any size.
Cell array	The length of the cell array specifies the number of inputs. The value of each cell specifies the size of the corresponding input. A scalar value N specifies a vector of size N. A value of -1 means that the corresponding port can accept scalar or vector signals of any size.
Comma-separated list of signal names	A list of signal names separated by commas. The software assigns each name to the corresponding port and signal. For example, if you enter position,velocity, the Mux block has two inputs, named position and velocity.

Specifying a nondouble value, such as single(3), is not supported.

Tips

If you specify a scalar for the Number of inputs parameter and all of the input ports are connected, as you draw a new signal line close to input side of a Mux block, the software adds a port and updates the parameter.

Programmatic Use

To set the block parameter value programmatically, use the set_param function.

Parameter:	Inputs
Values:	'2' (default) | scalar in quotes | vector in quotes | cell array in quotes | comma-separated list of signal names in quotes
Data Types:	char | string

Example: set_param(gcb,'Inputs','5')

Example: set_param(gcb,'Inputs','[2 3]')

Example: set_param(gcb,'Inputs','{3}')

Example: set_param(gcb,'Inputs','position,velocity')

Display option — Block icon appearance

bar (default) | signals | none

Block icon appearance, specified as bar, signals, or none.

• bar — Displays no text

• signals — Displays the input signal names

• none — Displays the type of block (Mux)

Resize the block as necessary to fit the text on the block icon.

Programmatic Use

To set the block parameter value programmatically, use the set_param function.

Parameter:	DisplayOption
Values:	'bar' (default) | 'signals' | 'none'

Example: set_param(gcb,'DisplayOption','signals')

Block Characteristics

Data Types	Boolean | double | enumerated | fixed point | half | integer | single
Direct Feedthrough	yes
Multidimensional Signals	no
Variable-Size Signals	no
Zero-Crossing Detection	no

Extended Capabilities

C/C++ Code Generation

Generate C and C++ code using Simulink® Coder™.

Actual data type or capability support depends on block implementation.

To improve the efficiency of generated code, use a Vector Concatenate block instead of a Mux block. The Vector Concatenate block creates a nonvirtual vector.

HDL Code Generation

Generate VHDL, Verilog and SystemVerilog code for FPGA and ASIC designs using HDL Coder™.

HDL Coder™ provides additional configuration options that affect HDL implementation and synthesized logic.

HDL Architecture

This block has one default HDL architecture.

HDL Block Properties

ConstrainedOutputPipeline	Number of registers to place at the outputs by moving existing delays within your design. Distributed pipelining does not redistribute these registers. The default is 0. For more details, see ConstrainedOutputPipeline (HDL Coder).
InputPipeline	Number of input pipeline stages to insert in the generated code. Distributed pipelining and constrained output pipelining can move these registers. The default is 0. For more details, see InputPipeline (HDL Coder).
OutputPipeline	Number of output pipeline stages to insert in the generated code. Distributed pipelining and constrained output pipelining can move these registers. The default is 0. For more details, see OutputPipeline (HDL Coder).

Complex Data Support

This block supports code generation for complex signals.

Restrictions

Buses are not supported for HDL code generation.

PLC Code Generation
Generate Structured Text code using Simulink® PLC Coder™.

Fixed-Point Conversion

Design and simulate fixed-point systems using Fixed-Point Designer™.

Actual data type or capability support depends on block implementation.

Version History

Introduced before R2006a