Stratix IV IO pin Configuration Error(cant turn on open drain option...)

[Altera_Forum]

I’m using the TR4(Stratix IV GX FPGA) development kit to interface with a Linear Technology ADC(LTM9012). I’m using the HSMC pins on the TR4 board(HSMC_A) to interface with a Linear Technology Analog to Digital Convertor demo board(the ADC is on a DC1732 Demo Board). The demo board has a FMC connector and I'm using a FMC-HSMC connector to interface with the Altera Development Kit. HSMC-A is used for this purpose.  

 The ADC has 4 different channels that spit out 14 bit LVDS data(serial). The ADC spits out two bits at a time(2-lane mode) and there are two bits per channel. Specifically, each channel comprises of two different lanes one for even bits and another for odd bits. I used the 'ALTLVDS_Rx' mega function and set the deserialization factor to 7. I plan to use 4 different LVDS receiver modules.  I understand that on the Quartus automatically assigns a pin for the corresponding 'inverting input' when an assignment is made for the non-inverting input. For instance, once the I/O standard for every node for the HSMC_RX_n and HSMC_RX_p are changed to 'LVDS' , the pin planner automatically generates the 'n' and 'p' node for every pin in the HSMC connector. This is irrespective of whether the node is 'p' or 'n'.    This means that once HSMCA_RX_p_[15] is assigned an LVDS standard, the pin planner automatically creates two nodes HSMCA_RX_p[15] and HSMCA_RX_p[15](n). In other words, assign an location to one node(such as HSMC_RX_p[15]), the location for the corresponding complementary node(HSMCA_RX_p[15](n)) is automatically assigned.    However, the pin planner still considers the HSMC_Rx_n[15] as a different node. When I compile the code or when I run the I/O assignment analysis, I get an error message that says "Can't turn on open-drain option for differential I/O pin HSMACRX_n[15])".  I' wondering if anyone else has encountered this problem or if there is a fix for this. Thank you in advance for your suggestions.

[Altera_Forum]

can you simply remove the _n pins from the top level pin list?

[Altera_Forum]

--- Quote Start ---  can you simply remove the _n pins from the top level pin list?  --- Quote End ---    It helps. Thanks. The code compiles.