diff --git a/firmware/cpld/sgpio_if/top.ucf b/firmware/cpld/sgpio_if/top.ucf
index db741928..e03f0385 100755
--- a/firmware/cpld/sgpio_if/top.ucf
+++ b/firmware/cpld/sgpio_if/top.ucf
@@ -33,28 +33,28 @@ NET "DA<2>" LOC="41" |IOSTANDARD=LVCMOS33 | TNM=adc_data;
 NET "DA<1>" LOC="42" |IOSTANDARD=LVCMOS33 | TNM=adc_data;
 NET "DA<0>" LOC="43" |IOSTANDARD=LVCMOS33 | TNM=adc_data;
 
-NET "DD<9>" LOC="17" |IOSTANDARD=LVCMOS33 | TNM=dac_data;
-NET "DD<8>" LOC="18" |IOSTANDARD=LVCMOS33 | TNM=dac_data;
-NET "DD<7>" LOC="19" |IOSTANDARD=LVCMOS33 | TNM=dac_data;
-NET "DD<6>" LOC="24" |IOSTANDARD=LVCMOS33 | TNM=dac_data;
-NET "DD<5>" LOC="28" |IOSTANDARD=LVCMOS33 | TNM=dac_data;
-NET "DD<4>" LOC="29" |IOSTANDARD=LVCMOS33 | TNM=dac_data;
-NET "DD<3>" LOC="30" |IOSTANDARD=LVCMOS33 | TNM=dac_data;
-NET "DD<2>" LOC="32" |IOSTANDARD=LVCMOS33 | TNM=dac_data;
-NET "DD<1>" LOC="33" |IOSTANDARD=LVCMOS33;
-NET "DD<0>" LOC="34" |IOSTANDARD=LVCMOS33;
+NET "DD<9>" LOC="17" |IOSTANDARD=LVCMOS33 | SLEW=SLOW | TNM=dac_data;
+NET "DD<8>" LOC="18" |IOSTANDARD=LVCMOS33 | SLEW=SLOW | TNM=dac_data;
+NET "DD<7>" LOC="19" |IOSTANDARD=LVCMOS33 | SLEW=SLOW | TNM=dac_data;
+NET "DD<6>" LOC="24" |IOSTANDARD=LVCMOS33 | SLEW=SLOW | TNM=dac_data;
+NET "DD<5>" LOC="28" |IOSTANDARD=LVCMOS33 | SLEW=SLOW | TNM=dac_data;
+NET "DD<4>" LOC="29" |IOSTANDARD=LVCMOS33 | SLEW=SLOW | TNM=dac_data;
+NET "DD<3>" LOC="30" |IOSTANDARD=LVCMOS33 | SLEW=SLOW | TNM=dac_data;
+NET "DD<2>" LOC="32" |IOSTANDARD=LVCMOS33 | SLEW=SLOW | TNM=dac_data;
+NET "DD<1>" LOC="33" |IOSTANDARD=LVCMOS33 | SLEW=SLOW | TNM=dac_data;
+NET "DD<0>" LOC="34" |IOSTANDARD=LVCMOS33 | SLEW=SLOW | TNM=dac_data;
 
-NET "HOST_DIRECTION" LOC="71" |IOSTANDARD=LVCMOS33;
-NET "HOST_DISABLE"   LOC="76" |IOSTANDARD=LVCMOS33;
-NET "HOST_CAPTURE"   LOC="91" |IOSTANDARD=LVCMOS33 | TNM=to_host;
-NET "HOST_DATA<7>"   LOC="77" |IOSTANDARD=LVCMOS33 | TNM=to_host;
-NET "HOST_DATA<6>"   LOC="61" |IOSTANDARD=LVCMOS33 | TNM=to_host;
-NET "HOST_DATA<5>"   LOC="64" |IOSTANDARD=LVCMOS33 | TNM=to_host;
-NET "HOST_DATA<4>"   LOC="67" |IOSTANDARD=LVCMOS33 | TNM=to_host;
-NET "HOST_DATA<3>"   LOC="72" |IOSTANDARD=LVCMOS33 | TNM=to_host;
-NET "HOST_DATA<2>"   LOC="74" |IOSTANDARD=LVCMOS33 | TNM=to_host;
-NET "HOST_DATA<1>"   LOC="79" |IOSTANDARD=LVCMOS33 | TNM=to_host;
-NET "HOST_DATA<0>"   LOC="89" |IOSTANDARD=LVCMOS33 | TNM=to_host;
+NET "HOST_DIRECTION" LOC="71" |IOSTANDARD=LVCMOS33 | SLEW=SLOW;
+NET "HOST_DISABLE"   LOC="76" |IOSTANDARD=LVCMOS33 | SLEW=SLOW;
+NET "HOST_CAPTURE"   LOC="91" |IOSTANDARD=LVCMOS33 | SLEW=SLOW | TNM=to_host;
+NET "HOST_DATA<7>"   LOC="77" |IOSTANDARD=LVCMOS33 | SLEW=SLOW | TNM=to_host;
+NET "HOST_DATA<6>"   LOC="61" |IOSTANDARD=LVCMOS33 | SLEW=SLOW | TNM=to_host;
+NET "HOST_DATA<5>"   LOC="64" |IOSTANDARD=LVCMOS33 | SLEW=SLOW | TNM=to_host;
+NET "HOST_DATA<4>"   LOC="67" |IOSTANDARD=LVCMOS33 | SLEW=SLOW | TNM=to_host;
+NET "HOST_DATA<3>"   LOC="72" |IOSTANDARD=LVCMOS33 | SLEW=SLOW | TNM=to_host;
+NET "HOST_DATA<2>"   LOC="74" |IOSTANDARD=LVCMOS33 | SLEW=SLOW | TNM=to_host;
+NET "HOST_DATA<1>"   LOC="79" |IOSTANDARD=LVCMOS33 | SLEW=SLOW | TNM=to_host;
+NET "HOST_DATA<0>"   LOC="89" |IOSTANDARD=LVCMOS33 | SLEW=SLOW | TNM=to_host;
 
 TIMEGRP "adc_data" OFFSET = IN 16 ns BEFORE "CODEC_X2_CLK";