Check subsystem or model for HDL code generation compatibility


output = checkhdl('system')


checkhdl generates an HDL Code Generation Check Report, saves the report to the target folder, and displays the report in a new window. Before generating HDL code, use checkhdl to check your subsystems or models.


Running this command can activate the Open at simulation start setting for blocks such as the Scope block and therefore invoke the block.

The report lists compatibility errors with a link to each block or subsystem that caused a problem. To highlight and display incompatible blocks, click each link in the report while keeping the model open.

The report file name is system_report.html. system is the name of the subsystem or model passed in to checkhdl.

When a model or subsystem passes checkhdl, that does not imply code generation will complete. checkhdl does not verify all block parameters.

checkhdl(bdroot) examines the current model for HDL code generation compatibility.

checkhdl('dut') examines the specified DUT model name, model reference name, or subsystem name with full hierarchical path.

checkhdl(gcb) examines the currently selected subsystem.

output = checkhdl('system')

does not generate a report. Instead, it returns a 1xN struct array with one entry for each error, warning, or message. system specifies a model or the full block path for a subsystem at any level of the model hierarchy.

The name-value pair arguments that you specify with makehdl and makehdltb can also be specified with checkhdl. For a list of name-value pair arguments, see Name-Value Pair Arguments.

checkhdl reports three levels of compatibility problems:

  • Errors: cause the code generation process to terminate. The report must not contain errors to continue with HDL code generation.

  • Warnings: indicate problems in the generated code, but allow HDL code generation to continue.

  • Messages: indication that some data types have special treatment. For example, the HDL Coder™ software automatically converts single-precision floating-point data types to double-precision because VHDL® and Verilog® do not support single-precision data types.


Check the subsystem symmetric_fir within the model sfir_fixed for HDL code generation compatibility and generate a compatibility report.


Check the subsystem symmetric_fir_err within the model sfir_fixed_err for HDL code generation compatibility, and return information on problems encountered in the struct output.

output = checkhdl('sfir_fixed_err/symmetric_fir_err')
### Starting HDL Check.
### HDL Check Complete with 4 errors, warnings and messages.

The following MATLAB® commands display the top-level structure of the struct output, and its first cell.

output = 

1x4 struct array with fields:


ans = 

       path: 'sfir_fixed_err/symmetric_fir_err/Product'
       type: 'block'
    message: 'Unhandled mixed double and non-double datatypes at ports of block'
      level: 'Error'
Introduced in R2006b