The Quartus® II software version 8.0 and version 8.1 incorrectly enable an internal resistor between two I/Os of a side bank dedicated differential input pair when each I/O is configured as single-ended and any of the following conditions are true:
- The current strength is not specified
- The input parallel on chip termination (OCT) option for the I/O is enabled
- The output series OCT option for the I/O is enabled
This problem affects only Stratix® III and Stratix® IV devices.
If both I/Os in this pair are input-only, the internal resistor is enabled incorrectly only if the input parallel termination option for either input is enabled. This resistor may cause the I/O pin to malfunction when it is single-ended by reducing the complementary pin voltage.
This problem is fixed in the Quartus II software version 8.0 SP1 and version 9.0 and above. Get the latest Quartus II software version from the Download Center.
To correct this problem in the Quartus II software version 8.0 and 8.1, if you cannot upgrade to the latest version, download and install patch 0.22 for version 8.0 and patch 0.50 for version 8.1 from the following locations:
Patch for Quartus II software version 8.0:
Quartus II 8.0 Patch 0.22 for PC
Quartus II 8.0 Patch 0.22 for PC readme.txt
Quartus II 8.0 Patch 0.22 for Linux
Quartus II 8.0 Patch 0.22 for Linux readme.txt
Patch for Quartus II software version 8.1:
Quartus II 8.1 Patch 0.50 for PC
Quartus II 8.1 Patch 0.50 for PC readme.txt
Quartus II 8.1 Patch 0.50 for Linux
Quartus II 8.1 Patch 0.50 for Linux readme.txt