A black-box is a module in which only the input and output ports of module is available for the designers to connect and integrate with the other modules:
The below is an example of a 2 to 1 multiplexer black-box module:
/////////////—————–////////////////////
module mux2_1 (
input a,
input b,
input sel,
output reg out
);
endmodule
/////////////////————-/////////////////
In the above Verilog code there is no logic written inside module except the input and output ports.
In scenarios like,
–
# Intellectual Property (IP): IP developed by the designers can be protected using black-boxing technique before delivering it to the other designers,
# Complexity: Complex modules which are not easy to understand and optimize can be black-boxed.
# Integration with 3rd Party IPs: When working on the 3rd party IP integration, the designers might not have access to the internal logic details of the IPs, as it is been protected using black-boxing technique.
# Design Partitioning: While partitioning the larger design, the designer partition the design into smaller modules, these smaller modules can be black-boxed to hide the internal logic.
# Timing Closure: Black-boxing the module can help improve the timing as the synthesize tool can optimize the module without considering the internal logic of the module.