+
+# definition of Clock nets:
+NET "ck_1356meg" TNM_NET = "clk_net_1356" ;
+NET "ck_1356megb" TNM_NET = "clk_net_1356b" ;
+NET "pck0" TNM_NET = "clk_net_pck0" ;
+NET "spck" TNM_NET = "clk_net_spck" ;
+
+# Timing specs of clock nets:
+TIMEGRP "clk_net_1356_all" = "clk_net_1356" "clk_net_1356b" ;
+TIMESPEC "TS_1356MHz" = PERIOD "clk_net_1356_all" 74 ns HIGH 37 ns ;
+TIMESPEC "TS_24MHz" = PERIOD "clk_net_pck0" 42 ns HIGH 21 ns ;
+TIMESPEC "TS_4MHz" = PERIOD "clk_net_spck" 250 ns HIGH 125 ns ;
+