3.5.1.19.5 Top-level Driver Functions

When all interfaces of a HLS module are either AXI4 target or AXI4 initiator, that means an attached processor can initialize/retrieve all input/output data of the HLS module and control the HLS module's execution. Then SmartHLS™ will also generate the following driver functions to make it convenient for replacing the original top-level function in a software program.

// Initializes all input argument data, starts the HLS module, waits for its completion, and retrieves output argument data and return value.
// Can be used as a direct replacement to the original top-level function.
// Has the same arguments and return type as the top-level function.
RETURN_TYPE MyTopFunc_hls_driver(...);

// Initializes all input argument data, starts the HLS module
// Can be used to start the HLS module and resume to execute other parts of the software while the HLS module is running, then later call the _join_and_read_output function below.
// The arguments are the input arguments of the top-level functions.
void MyTopFunc_write_input_and_start(...);

// Blocking function that waits for the HLS module to finish the execution, and retrieves output argument data and return value.
// The arguments are the output arguments of the top-level functions.
RETURN_TYPE MyTopFunc_join_and_read_output(...);

The above top-level driver functions use the individual argument or module control drivers (as described in above sections) under the hood.

To make all interfaces accessible by an attached processor, one can use the default interface pragma to set the default interface to AXI4 target for all arguments and module control (see 3.6.1.19 Default All Interfaces to Use AXI4 Target ), and then add pragmas for axi_initiator interface or to configure non-default options.