AR# 38233

Design Assistant for XST Help resolving "HDLCompiler:508: illegal recursive module instantiation of %s" errors

Description

Refer to this Answer Record for help resolving "HDLCompiler:508: illegal recursive module instantiation of %s" errors.

Note: This Answer Record is a part of the Xilinx Solution Center for XST (Xilinx Answer 38927). The Xilinx Solution Center for XST is available to address all questions related to XST. Whether you are starting a new design or troubleshooting a problem, use the Solution Center for XST to guide you to the right information.

Solution

This error occurs if a module attempts to create an instance of itself within the definition (module/endmodule keyword pair of the module).

WHAT NEXT:

This points to a serious design error. Either rename the parent module, or the instanced module.

EXAMPLE:

Consider the following RTL:

1: module top();
2:
3: top inst_of_top;
4:
5:endmodule

There is an instance of module top within the definition of module top. This can be fixed by changing the module name "top" in either lines 1 or 3.

Linked Answer Records

Master Answer Records

Answer Number Answer Title Version Found Version Resolved
38927 Xilinx Solution Center for XST N/A N/A

Associated Answer Records

Answer Number Answer Title Version Found Version Resolved
40379 Design Assistant for XST Help understanding the XST report to resolve errors\warnings N/A N/A
AR# 38233
Date 12/15/2012
Status Active
Type General Article