Updated GPIO yellow block for SKARAB

I have updated the GPIO yellow block, so that it now includes the SKARAB gpio, led, sync_in, sync_out and aux_clk_diff. No I/O timing contsraints added for now.

jasper_library/platforms/skarab.yaml

@@ -160,7 +160,25 @@ pins:
       - AW34
       - BB33
       - BA33
-      - AY33
+      - AY33      
+  aux_clk_diff_p:
+    iostd: LVDS
+    loc: AU20
+  aux_clk_diff_n:
+    iostd: LVDS
+    loc: AV19
+  sync_in_p:
+    iostd: LVDS
+    loc: AT21
+  sync_in_n:
+    iostd: LVDS
+    loc: AU21
+  sync_out_p:
+    iostd: LVDS
+    loc: AW21
+  sync_out_n:
+    iostd: LVDS
+    loc: AY21
   FPGA_ATX_PSU_KILL:
     iostd: LVCMOS18
     loc: BD10
@@ -757,21 +775,6 @@ pins:
   SPARTAN_CLK:
     iostd: LVCMOS18
     loc: BA26
-  AUX_CLK_P:
-    iostd: LVDS
-  AUX_CLK_N:
-    iostd: LVDS
-    loc: AV19
-  AUX_SYNCI_P:
-    iostd: LVDS
-  AUX_SYNCI_N:
-    iostd: LVDS
-    loc: AU21
-  AUX_SYNCO_P:
-    iostd: LVDS
-  AUX_SYNCO_N:
-    iostd: LVDS
-    loc: AY21
   MONITOR_ALERT_N:
     iostd: LVCMOS18
     loc: BB13

jasper_library/yellow_blocks/gpio.py

@@ -18,7 +18,7 @@ def initialize(self):
             self.pad_bitwidth = self.bitwidth
 
         self.io_group = self.io_group.split(':')[-1] #iogroups have the form PLATFORM:GROUP (now would be a good time to change this!)
-        self.use_diffio = ((self.io_group in ['zdok0','zdok1','mdr','qsh','sync_in','sync_out']) and not self.use_single_ended)
+        self.use_diffio = ((self.io_group in ['zdok0','zdok1','mdr','qsh','sync_in','sync_out', 'aux_clk_diff']) and not self.use_single_ended)
 
         # Set the module we need to instantiate
         if self.use_diffio: