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AR# 34150

Spartan-6 FPGA MCB - Which unused MCB pins can be used as spare GPIO?


When unused by thememory controller interface,which MCB pins can be used as GPIO?


All MCB pins revert to GPIO when an MCB is unused.

Unused pins from an active MCB that revert to GPIO.

  • Higher order address or bank address pins not needed for a particular density device
  • DQ data bits not needed for a particular interface width
  • Reset and ODT signals when not needed for a memory standard
  • UDQS / UDQS_n strobes for x4 or x8 interfaces
  • All other interface pins are required for all MCB based design

Unused pins from an active MCB that do not revert to GPIO.

  • DM pins are paired - if only LDM is used, UDM is lost as GPIO
  • DM pins are required in all MCB designs to support variable burst length requests at the user interface
  • DQS are paired - if only DQS is used (single-ended strobe), DQS_n is lost as GPIO

Linked Answer Records

Associated Answer Records

Answer Number Answer Title Version Found Version Resolved
34265 MIG Solution Center - MIG Virtex-6 and Spartan-6 Top Issues N/A N/A
AR# 34150
Date Created 05/25/2010
Last Updated 02/27/2013
Status Active
Type General Article
  • Spartan-6 LX
  • Spartan-6 LXT
  • MIG