.. _set_custom_top_level_module:

set_custom_top_level_module
----------------------------


This TCL command specifies the top-level C function that will be compiled to
hardware by LegUp.
All descendant functions called by the top-level C function will be compiled by
LegUp.
By default the top-level is the "main" function.

When a custom top-level module is specified, a custom testbench will be needed
for running RTL simulation. Please see :ref:`set_custom_test_bench_module` and
:ref:`set_custom_test_bench_file`.


**Category**

HLS Constraints

**Value Type**

string

**Dependencies**

NONE

**Applicable Flows**

All devices and flows

**Test Status**

Actively in-use

**Examples**

    ``set_custom_top_level_module "accelerator_function"``

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