diff --git a/example_demo/alinx_ax7325b/ax7325b_spd_reader.xdc b/example_demo/alinx_ax7325b/ax7325b_spd_reader.xdc
index f6a0a2f..ce92be1 100644
--- a/example_demo/alinx_ax7325b/ax7325b_spd_reader.xdc
+++ b/example_demo/alinx_ax7325b/ax7325b_spd_reader.xdc
@@ -1,20 +1,33 @@
 ############## clock define##################
 create_clock -period 5.000 [get_ports sys_clk_p]
 set_property IOSTANDARD DIFF_SSTL15 [get_ports sys_clk_p]
-# no need to constrain N side (only P side) or else tool will analyze interclock oaths and show failure in timing
+# no need to create_clock for N side (only P side) or else tool will analyze interclock oaths and show failure in timing
 # https://support.xilinx.com/s/article/57109?language=en_US
 #create_clock -period 5.000 [get_ports sys_clk_n]
 set_property PACKAGE_PIN AE10 [get_ports sys_clk_p]
 set_property PACKAGE_PIN AF10 [get_ports sys_clk_n]
 set_property IOSTANDARD DIFF_SSTL15 [get_ports sys_clk_n]
+
 ############## SODIMM SPD define##################
 set_property IOSTANDARD LVCMOS33 [get_ports i2c_scl]
 set_property PACKAGE_PIN B20 [get_ports i2c_scl]
 set_property IOSTANDARD LVCMOS33 [get_ports i2c_sda]
 set_property PACKAGE_PIN C20 [get_ports i2c_sda]
+
 ############## fan define##################
 set_property IOSTANDARD LVCMOS25 [get_ports fan_pwm]
 set_property PACKAGE_PIN AE26 [get_ports fan_pwm]
+
 ############## key define##################
 set_property PACKAGE_PIN AG27 [get_ports i_rst_n]
 set_property IOSTANDARD LVCMOS25 [get_ports i_rst_n]
+
+##############LED define##################
+set_property PACKAGE_PIN A22 [get_ports {led[0]}]
+set_property IOSTANDARD LVCMOS15 [get_ports {led[0]}]
+set_property PACKAGE_PIN C19 [get_ports {led[1]}]
+set_property IOSTANDARD LVCMOS15 [get_ports {led[1]}]
+set_property PACKAGE_PIN B19 [get_ports {led[2]}]
+set_property IOSTANDARD LVCMOS15 [get_ports {led[2]}]
+set_property PACKAGE_PIN E18 [get_ports {led[3]}]
+set_property IOSTANDARD LVCMOS15 [get_ports {led[3]}]
\ No newline at end of file