diff --git a/projects/ad9213_dual_ebz/s10soc/system_constr.sdc b/projects/ad9213_dual_ebz/s10soc/system_constr.sdc
index 4a6463a83..d19656493 100755
--- a/projects/ad9213_dual_ebz/s10soc/system_constr.sdc
+++ b/projects/ad9213_dual_ebz/s10soc/system_constr.sdc
@@ -1,25 +1,11 @@
 
-create_clock -period  "10.000 ns"       -name sys_clk_100mhz      [get_ports {sys_clk}]
+create_clock -period  "10.000 ns"     -name sys_clk_100mhz      [get_ports {sys_clk}]
 create_clock -period  "3.2 ns"        -name ref_a_clk0          [get_ports {rx_ref_a_clk0}]
 create_clock -period  "3.2 ns"        -name ref_a_clk1          [get_ports {rx_ref_a_clk1}]
 create_clock -period  "3.2 ns"        -name ref_b_clk0          [get_ports {rx_ref_b_clk0}]
 create_clock -period  "3.2 ns"        -name ref_b_clk1          [get_ports {rx_ref_b_clk1}]
 create_clock -period  "3.2 ns"        -name device_clk          [get_ports {rx_device_clk_0}]
 
-# Asynchronous GPIOs
+set_input_delay -clock {device_clk} 0.2 [get_ports {rx_sysref_a}]
 
-foreach async_input {ad9213_a_gpio[*] ad9213_b_gpio[*]} {
-  set_false_path -to [get_ports $async_input]
-}
-
-foreach async_output {ad9213_a_rst ad9213_b_rst ad9213_a_gpio[*] ad9213_b_gpio[*]} {
-  set_false_path -to [get_ports $async_output]
-}
-
-derive_pll_clocks
-derive_clock_uncertainty
-
-# set_false_path -to [get_registers *sys_gpio_bd|readdata[12]*]
-# set_false_path -to [get_registers *sys_gpio_bd|readdata[13]*]
-#
 set_false_path -from [get_registers *altera_reset_synchronizer:alt_rst_sync_uq1|altera_reset_synchronizer_int_chain_out*]