Main Content


Check whether signal is zero

  • Library:
  • Simulink / Model Verification

    HDL Coder / Model Verification

  • Assertion block


The Assertion block checks whether any of the elements of the input signal are 0. If all of the elements are nonzero, the assertion is true (1) and the block does nothing. If not, the block halts the simulation and returns an error message by default.



expand all

Input signal to the assertion check.

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


expand all

Clearing this parameter disables the block and causes the model to behave as if the block does not exist. To enable or disable all verification blocks, regardless of the setting of this option, go to the Configuration Parameters window, click Diagnostics > Data Validity, expand the Advanced parameters section, and set Model Verification block enabling to Enable all or Disable all.

Command-Line Information

Parameter: enabled
Type: character vector
Values: 'on' | 'off'
Default: 'on'

Specify a MATLAB® expression to evaluate when the assertion fails. Because the expression is evaluated in the MATLAB workspace, define all variables used in the expression in that workspace.


To enable this parameter, select the Enable assertion parameter.

Command-Line Information

Parameter: callback
Type: character vector
Values: MATLAB expression
Default: ''

Select this parameter to stop the simulation when the check fails. Clear this parameter to display a warning and continue the simulation.

Command-Line Information

Parameter: stopWhenAssertionFail
Type: character vector
Values: 'on' | 'off'
Default: 'on'

Specify the sample time as a value other than -1. For more information, see Specify Sample Time.


This parameter is not visible unless it is explicitly set to a value other than -1. To learn more, see Blocks for Which Sample Time Is Not Recommended.

Programmatic Use

Block Parameter: SampleTime
Type: character vector
Values: scalar or vector
Default: '-1'

Block Characteristics

Data Types

Boolean | double | fixed point | half | integer | single

Direct Feedthrough


Multidimensional Signals


Variable-Size Signals


Zero-Crossing Detection


Extended Capabilities

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

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

Introduced before R2006a