AR# 38213

Design Assistant for XST - Help resolving "HDLCompiler:634:Net does not have a driver" warnings

Description

Refer to this Answer Record for help resolving a "HDLCompiler:634:Net does not have a driver" warning.

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 message appears when the Net or Reg does not have a driver.

WHAT NEXT:

Make surethe Net in question is connectedto a source, so that it can drive the net, and re-run XST.

EXAMPLE:

Consider the following RTL:

module top (din, clk, rst, out);
input din;
input clk;
input rst;
output out;

reg temp_reg;
reg OutData;

always @(posedge clk, posedge rst) begin
if(rst)
OutData <= temp_reg;
else
OutData <= din;
end

assign out = OutData;
endmodule



In the above example,the register 'temp_reg' is not driven by a source (driver).

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# 38213
Date 12/15/2012
Status Active
Type General Article
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