diff -Naur ml403project.old/data/system.ucf ml403project/data/system.ucf
--- ml403project.old/data/system.ucf	2008-04-24 11:29:30.000000000 -0400
+++ ml403project/data/system.ucf	2008-04-24 11:28:04.000000000 -0400
@@ -599,6 +599,10 @@
 Net fpga_0_FLASH_Mem_CE_pin<0> SLEW = FAST;
 Net fpga_0_FLASH_Mem_CE_pin<0> DRIVE = 8;
 
+###NET USB interrupt
+Net USB_INT_pin LOC=V5;
+Net USB_INT_pin IOSTANDARD = LVCMOS33;
+
 #### New GMAC Coregen Derived Constraints
 		
 NET "*tx_gmii_mii_clk*"    			TNM_NET = "clk_phy_tx_clk0";
diff -Naur ml403project.old/system.mhs ml403project/system.mhs
--- ml403project.old/system.mhs	2008-04-24 11:29:08.000000000 -0400
+++ ml403project/system.mhs	2008-04-24 11:28:29.000000000 -0400
@@ -18,6 +18,7 @@
  PARAMETER VERSION = 2.1.0
 
 
+ PORT USB_INT_pin = USB_INT, DIR = I
  PORT fpga_0_RS232_Uart_RX_pin = fpga_0_RS232_Uart_RX, DIR = I
  PORT fpga_0_RS232_Uart_TX_pin = fpga_0_RS232_Uart_TX, DIR = O
  PORT fpga_0_LEDs_4Bit_GPIO_IO_pin = fpga_0_LEDs_4Bit_GPIO_IO, DIR = IO, VEC = [0:3]
@@ -421,6 +422,6 @@
  PARAMETER C_HIGHADDR = 0x8180ffff
  BUS_INTERFACE SPLB = plb
  PORT Irq = EICC405EXTINPUTIRQ
- PORT Intr = RS232_Uart_Interrupt & LEDs_4Bit_IP2INTC_Irpt & LEDs_Positions_IP2INTC_Irpt & Push_Buttons_Position_IP2INTC_Irpt & IIC_EEPROM_IIC2INTC_Irpt & TriMode_MAC_GMII_TemacIntc0_Irpt & xps_timer_1_Interrupt & TriMode_MAC_GMII_fifo_IP2INTC_Irpt
+ PORT Intr = RS232_Uart_Interrupt & LEDs_4Bit_IP2INTC_Irpt & LEDs_Positions_IP2INTC_Irpt & Push_Buttons_Position_IP2INTC_Irpt & IIC_EEPROM_IIC2INTC_Irpt & TriMode_MAC_GMII_TemacIntc0_Irpt & xps_timer_1_Interrupt & TriMode_MAC_GMII_fifo_IP2INTC_Irpt & USB_INT
 END