diff --git a/projects/fmcomms2/zc706/system_constr.xdc b/projects/fmcomms2/zc706/system_constr.xdc
index 25b22387f..323bcd825 100644
--- a/projects/fmcomms2/zc706/system_constr.xdc
+++ b/projects/fmcomms2/zc706/system_constr.xdc
@@ -60,10 +60,13 @@ set_property  -dict {PACKAGE_PIN  AJ29  IOSTANDARD LVCMOS25} [get_ports spi_miso
 
 # spi pmod J58
 
-set_property  -dict {PACKAGE_PIN  AJ21    IOSTANDARD LVCMOS25}     [get_ports spi_udc_csn_tx]             ; ## PMOD1_0_LS
-set_property  -dict {PACKAGE_PIN  AK21    IOSTANDARD LVCMOS25}     [get_ports spi_udc_csn_rx]             ; ## PMOD1_1_LS
-set_property  -dict {PACKAGE_PIN  AB16    IOSTANDARD LVCMOS25}     [get_ports spi_udc_sclk]               ; ## PMOD1_3_LS
-set_property  -dict {PACKAGE_PIN  AB21    IOSTANDARD LVCMOS25}     [get_ports spi_udc_data]               ; ## PMOD1_2_LS
+set_property  -dict {PACKAGE_PIN  AJ21  IOSTANDARD LVCMOS25  PULLTYPE PULLUP} [get_ports spi_udc_csn_tx]  ; ## PMOD1_0_LS
+set_property  -dict {PACKAGE_PIN  Y20   IOSTANDARD LVCMOS25  PULLTYPE PULLUP} [get_ports spi_udc_csn_rx]  ; ## PMOD1_4_LS
+set_property  -dict {PACKAGE_PIN  AB16  IOSTANDARD LVCMOS25} [get_ports spi_udc_sclk]                     ; ## PMOD1_3_LS
+set_property  -dict {PACKAGE_PIN  AK21  IOSTANDARD LVCMOS25} [get_ports spi_udc_data]                     ; ## PMOD1_1_LS
+
+set_property  -dict {PACKAGE_PIN  AB21  IOSTANDARD LVCMOS25} [get_ports gpio_muxout_tx]                   ; ## PMOD1_2_LS
+set_property  -dict {PACKAGE_PIN  AC18  IOSTANDARD LVCMOS25} [get_ports gpio_muxout_rx]                   ; ## PMOD1_6_LS
 
 # clocks
 
diff --git a/projects/fmcomms2/zc706/system_top.v b/projects/fmcomms2/zc706/system_top.v
index 91f6322f9..df3db223a 100644
--- a/projects/fmcomms2/zc706/system_top.v
+++ b/projects/fmcomms2/zc706/system_top.v
@@ -93,6 +93,8 @@ module system_top (
   enable,
   txnrx,
 
+  gpio_muxout_tx,
+  gpio_muxout_rx,
   gpio_resetb,
   gpio_sync,
   gpio_en_agc,
@@ -161,6 +163,8 @@ module system_top (
   output          enable;
   output          txnrx;
 
+  inout           gpio_muxout_tx;
+  inout           gpio_muxout_rx;
   inout           gpio_resetb;
   inout           gpio_sync;
   inout           gpio_en_agc;
@@ -217,11 +221,13 @@ module system_top (
 
   // instantiations
 
-  ad_iobuf #(.DATA_WIDTH(17)) i_iobuf (
-    .dio_t (gpio_t[48:32]),
-    .dio_i (gpio_o[48:32]),
-    .dio_o (gpio_i[48:32]),
-    .dio_p ({ gpio_txnrx,
+  ad_iobuf #(.DATA_WIDTH(19)) i_iobuf (
+    .dio_t (gpio_t[50:32]),
+    .dio_i (gpio_o[50:32]),
+    .dio_o (gpio_i[50:32]),
+    .dio_p ({ gpio_muxout_tx,
+              gpio_muxout_rx,
+              gpio_txnrx,
               gpio_enable,
               gpio_resetb,
               gpio_sync,
diff --git a/projects/fmcomms2/zed/system_constr.xdc b/projects/fmcomms2/zed/system_constr.xdc
index 58038d19b..37fa7963c 100644
--- a/projects/fmcomms2/zed/system_constr.xdc
+++ b/projects/fmcomms2/zed/system_constr.xdc
@@ -61,9 +61,12 @@ set_property  -dict {PACKAGE_PIN  D21  IOSTANDARD LVCMOS25} [get_ports spi_miso]
 # spi pmod JA1
 
 set_property  -dict {PACKAGE_PIN  Y11    IOSTANDARD LVCMOS33}     [get_ports spi_udc_csn_tx]       ; ## JA1
-set_property  -dict {PACKAGE_PIN  AA11   IOSTANDARD LVCMOS33}     [get_ports spi_udc_csn_rx]       ; ## JA2
+set_property  -dict {PACKAGE_PIN  AB11   IOSTANDARD LVCMOS33}     [get_ports spi_udc_csn_rx]       ; ## JA7
 set_property  -dict {PACKAGE_PIN  AA9    IOSTANDARD LVCMOS33}     [get_ports spi_udc_sclk]         ; ## JA4
-set_property  -dict {PACKAGE_PIN  Y10    IOSTANDARD LVCMOS33}     [get_ports spi_udc_data]         ; ## JA3
+set_property  -dict {PACKAGE_PIN  AA11   IOSTANDARD LVCMOS33}     [get_ports spi_udc_data]         ; ## JA2
+
+set_property  -dict {PACKAGE_PIN  Y10    IOSTANDARD LVCMOS33}     [get_ports gpio_muxout_tx]       ; ## JA3
+set_property  -dict {PACKAGE_PIN  AB9    IOSTANDARD LVCMOS33}     [get_ports gpio_muxout_rx]       ; ## JA9
 
 # clocks
 
diff --git a/projects/fmcomms2/zed/system_top.v b/projects/fmcomms2/zed/system_top.v
index 38f758826..05ef95d01 100644
--- a/projects/fmcomms2/zed/system_top.v
+++ b/projects/fmcomms2/zed/system_top.v
@@ -103,6 +103,8 @@ module system_top (
   txnrx,
   enable,
 
+  gpio_muxout_tx,
+  gpio_muxout_rx,
   gpio_resetb,
   gpio_sync,
   gpio_en_agc,
@@ -181,6 +183,8 @@ module system_top (
   output          txnrx;
   output          enable;
 
+  inout           gpio_muxout_tx;
+  inout           gpio_muxout_rx;
   inout           gpio_resetb;
   inout           gpio_sync;
   inout           gpio_en_agc;
@@ -222,11 +226,13 @@ module system_top (
 
   // instantiations
 
-  ad_iobuf #(.DATA_WIDTH(49)) i_iobuf_gpio (
-    .dio_t ({gpio_t[48:0]}),
-    .dio_i ({gpio_o[48:0]}),
-    .dio_o ({gpio_i[48:0]}),
-    .dio_p ({ gpio_txnrx,
+  ad_iobuf #(.DATA_WIDTH(51)) i_iobuf_gpio (
+    .dio_t ({gpio_t[50:0]}),
+    .dio_i ({gpio_o[50:0]}),
+    .dio_o ({gpio_i[50:0]}),
+    .dio_p ({ gpio_muxout_tx,
+              gpio_muxout_rx,
+              gpio_txnrx,
               gpio_enable,
               gpio_resetb,
               gpio_sync,