regarding the Stratix IV GX FPGA development kit, see:http://media.digikey.com/pdf/data%20sheets/altera%20pdfs/dk-dev-4sgx230n-c2.pdf specifically, regarding pages 40-49 in the Stratix IV E FPGA Development Board Reference Manual, see: http://www.altera.com/literature/manual/rm_sive_fpga_dev_board.pdf more specifically, regarding a statement on page 41 in the above reference manual doc says, "The HSMC interface has programmable bi-directional I/O pins that can be used as 2.5-V LVCMOS, which is 3.3-V LVTTL-compatible. These pins can also be used as various differential I/O standards including, but not limited to, LVDS, mini-LVDS, and RSDS with up to 17 full-duplex channels." question: Can I configure the LVDS channels to transfer data all in one direction or the other; so for example, instead of having 17 full duplex LVDS transmit/receive channels, I can have 34 LVDS transmit channels per HSMC I/O port? context of this question: I have a 4 GS/s DAC (digital to analog converter) with 12 bit resolution in mind that I want to attached as a daughter card to the HSMC I/O port of the Stratix IV GX board. There are a total of 48 input channels into the DAC (each of 4 samples is 12 bit wide). To reduce DAC resolution, I can use 8 instead of 12 bits; therefore requiring 32 LVDS inputs. Given this context, please address the above question. Thanks. Eric
All Stratix family devices have dedicated LVDS Rx and Tx hardware, you can't use Tx channels for LVDS Rx. To learn about the capabilities of indivual pins, you can consult the Quartus II Pin Planner tool or the device pinout documents.