[SOLVED] how I know the fpga_0_RS232_RX

how I know the fpga_0_RS232_RX_pin of Atlys spartan-6

I want to configure RS232 of an ATLYS SPARTAN 6 XC6SLX45 I want to configure the pin fpga_0_RS232_RX_pin on the board but I don't know how to configure the suitable pin for it.How can I do that? system.ucf:

#  Generic Template
Net fpga_0_RS232_RX_pin LOC=;
Net fpga_0_RS232_TX_pin LOC=;
Net fpga_0_clk_1_sys_clk_pin LOC = "L15" | IOSTANDARD = "LVCMOS33";
Net fpga_0_rst_1_sys_rst_pin LOC = "T15" | IOSTANDARD = "LVCMOS33" | TIG;
Net fpga_0_clk_1_sys_clk_pin TNM_NET = sys_clk_pin;
TIMESPEC TS_sys_clk_pin = PERIOD sys_clk_pin 100000 kHz;

Solution

See the website for the ATLYS board, they have a file called the master UCF that list every pin on the board.

You will find the following line in that file that give your answer:

# USB UART Connector
NET "UartRx" LOC = "A16"; # Bank = 0, Pin name = IO_L66N_SCP0, Sch name = USBB-RXD
NET "UartTx" LOC = "B16"; # Bank = 0, Pin name = IO_L66P_SCP1, Sch name = USBB-TXD

Unfortunately, the Digilent file doesn't give the IOSTANDARD, but everything on that board is 3.3V except bank 3 which is 1.8V. So the line you need are:

Net fpga_0_RS232_RX_pin LOC = "A16" | IOSTANDARD = LVCMOS33;
Net fpga_0_RS232_TX_pin LOC = "B16" | IOSTANDARD = LVCMOS33;