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AR# 24835

Modelsim/VCS/NCSIM - "Warning-[SIOB] Select index out of bounds"

Description

When I run simulation with Modelsim or VCS or NCSIM , the following message appears:

"In module instance % in module %
Warning-[SIOB] Select index out of bounds"

or

"Bit-select into 'memp' is out of bounds"

Solution

ModelSim, VCS, and NCSIM issue a warning on the code that is never executed. Therefore, this warning can be safely ignored.

For example, if you set block RAM read and write port width (port_width) to 1 in the model:

Case (port_width)
1: .....
2: .....
4: ..

ModelSim, VCS, and NCSIM issue a warning for case items 2, 4, etc., which are out of bounds in the index, even if the set port width = 1. In fact, 2, 4, etc.,are never executed.
AR# 24835
Date Created 09/04/2007
Last Updated 03/05/2013
Status Active
Type General Article
Tools
  • ISE - 10.1
  • ISE Design Suite - 11.1
  • ISE Design Suite - 11.2
  • More
  • ISE Design Suite - 11.3
  • ISE Design Suite - 11.4
  • ISE Design Suite - 11.5
  • ISE Design Suite - 12.1
  • ISE Design Suite - 12.2
  • Less