diff --git a/ossc.qsf b/ossc.qsf
index dd36cbb..539082b 100644
--- a/ossc.qsf
+++ b/ossc.qsf
@@ -240,18 +240,11 @@ set_global_assignment -name SDC_FILE ossc.sdc
 set_global_assignment -name CDF_FILE output_files/Chain1.cdf
 set_global_assignment -name SIGNALTAP_FILE output_files/ossc_la.stp
 set_global_assignment -name QIP_FILE rtl/char_array.qip
-set_instance_assignment -name FAST_OUTPUT_ENABLE_REGISTER ON -to HDMI_TX_DE
-set_instance_assignment -name FAST_OUTPUT_ENABLE_REGISTER ON -to HDMI_TX_HS
-set_instance_assignment -name FAST_OUTPUT_ENABLE_REGISTER ON -to HDMI_TX_PCLK
-set_instance_assignment -name FAST_OUTPUT_ENABLE_REGISTER ON -to HDMI_TX_VS
-set_instance_assignment -name FAST_OUTPUT_ENABLE_REGISTER ON -to HDMI_TX_BD
-set_instance_assignment -name FAST_OUTPUT_ENABLE_REGISTER ON -to HDMI_TX_GD
-set_instance_assignment -name FAST_OUTPUT_ENABLE_REGISTER ON -to HDMI_TX_RD
-set_instance_assignment -name FAST_OUTPUT_REGISTER ON -to HDMI_TX_DE
-set_instance_assignment -name FAST_OUTPUT_REGISTER ON -to HDMI_TX_HS
-set_instance_assignment -name FAST_OUTPUT_REGISTER ON -to HDMI_TX_PCLK
-set_instance_assignment -name FAST_OUTPUT_REGISTER ON -to HDMI_TX_VS
-set_instance_assignment -name FAST_OUTPUT_REGISTER ON -to HDMI_TX_BD
-set_instance_assignment -name FAST_OUTPUT_REGISTER ON -to HDMI_TX_GD
-set_instance_assignment -name FAST_OUTPUT_REGISTER ON -to HDMI_TX_RD
+set_instance_assignment -name FAST_OUTPUT_REGISTER ON -to HDMI_TX_BD[0]
+set_instance_assignment -name FAST_OUTPUT_REGISTER ON -to HDMI_TX_BD[3]
+set_instance_assignment -name FAST_OUTPUT_REGISTER ON -to HDMI_TX_BD[7]
+set_instance_assignment -name FAST_OUTPUT_REGISTER ON -to HDMI_TX_GD[7]
+set_instance_assignment -name FAST_OUTPUT_REGISTER ON -to HDMI_TX_RD[1]
+set_instance_assignment -name FAST_OUTPUT_REGISTER ON -to HDMI_TX_RD[5]
+set_instance_assignment -name FAST_OUTPUT_REGISTER ON -to HDMI_TX_RD[7]
 set_instance_assignment -name PARTITION_HIERARCHY root_partition -to | -section_id Top
\ No newline at end of file
diff --git a/ossc.sdc b/ossc.sdc
index 788c142..a02b729 100644
--- a/ossc.sdc
+++ b/ossc.sdc
@@ -53,9 +53,10 @@ foreach_in_collection c [get_clocks "pclk_1x pclk_*_source"] {
     set_input_delay -clock $c -max $TVP_dmax $critinputs -add_delay
 }
 
-# output delay constraints
+# output delay constraints as documented in the IT6613 datasheet
+# -- increased IT_Tsu from 1.0 to 1.5 due to #52
 set IT_Tsu 1.5
-set IT_Th -0.3
+set IT_Th -0.5
 set critoutputs_hdmi [get_ports {HDMI_TX_RD* HDMI_TX_GD* HDMI_TX_BD* HDMI_TX_DE HDMI_TX_HS HDMI_TX_VS}]
 foreach_in_collection c [get_clocks pclk_*_out] {
     set_output_delay -clock $c -min $IT_Th $critoutputs_hdmi -add