gistfile1.txt

IOBUF #(
   .DRIVE(12), // Specify the output drive strength
   .IBUF_DELAY_VALUE("0"),   // Specify the amount of added input delay for the buffer, "0"-"16" (Spartan-3A only)
   .IFD_DELAY_VALUE("AUTO"), // Specify the amount of added delay for input register,  "AUTO", "0"-"8" (Spartan-3A only)
   .IOSTANDARD("DEFAULT"), // Specify the I/O standard
   .SLEW("SLOW") // Specify the output slew rate
) IOBUF_gpmc_ad[15:0] (
   .O(gpmc_ad_in),    // Buffer output
   .IO(GPMC_AD),		// Buffer inout port (connect directly to top-level port)
   .I(gpmc_ad_out),	// Buffer input
   .T(~GPMC_DIR)    	// 3-state enable input, high=input, low=output
);