diff --git a/configs/samd20-xplained/README.txt b/configs/samd20-xplained/README.txt
index 8055911a7ca..c968c214f8c 100644
--- a/configs/samd20-xplained/README.txt
+++ b/configs/samd20-xplained/README.txt
@@ -405,12 +405,12 @@ Serial Consoles
 
   SERCOM4 is available on connectors EXT1 and EXT3
 
-    PIN   EXT1  EXT3  GPIO  Function
-    ----  ---- ------ -----------
-     13   PB09   PB13 SERCOM4 / USART RX
-     14   PB08   PB12 SERCOM4 / USART TX
-     19   19          GND
-     20   20          VCC
+    PIN   EXT1 EXT3 GPIO Function
+    ----  ---- ---- ------------------
+     13   PB09 PB13 SERCOM4 / USART RX
+     14   PB08 PB12 SERCOM4 / USART TX
+     19   19        GND
+     20   20        VCC
 
   If you have a TTL to RS-232 converter then this is the most convenient
   serial console to use.  It is the default in all of these configurations.
diff --git a/configs/samd20-xplained/include/board.h b/configs/samd20-xplained/include/board.h
index e94db4d8dc4..216e38c0bfe 100644
--- a/configs/samd20-xplained/include/board.h
+++ b/configs/samd20-xplained/include/board.h
@@ -56,13 +56,14 @@
 /* Clocking *************************************************************************/
 /* Overview
  *
- * OSC8M             Output = 8MHz
- *  `- GCLK1         Input  = 8MHz  Prescaler    = 1 output         = 8MHz
- *      `- DFLL      Input  = 8MHz  Multiplier   = 6 output         = 48MHz
- *          `- PM    Input  = 48Mhz CPU divider  = 1 CPU frequency  = 48MHz
- *                                  APBA divider = 1 APBA frequency = 48MHz
- *                                  APBB divider = 1 APBB frequency = 48MHz
- *                                  APBC divider = 1 APBC frequency = 48MHz
+ * OSC8M              Output = 8MHz
+ *  `- GCLK1          Input  = 8MHz  Prescaler    = 1 output         = 8MHz
+ *      `- DFLL       Input  = 8MHz  Multiplier   = 6 output         = 48MHz
+ *          `- GCLK0  Input  = 48MHz Prescaler    = 1 output         = 48MHz
+ *              `- PM Input  = 48Mhz CPU divider  = 1 CPU frequency  = 48MHz
+ *                                   APBA divider = 1 APBA frequency = 48MHz
+ *                                   APBB divider = 1 APBB frequency = 48MHz
+ *                                   APBC divider = 1 APBC frequency = 48MHz
  *
  * The SAMD20 Xplained Pro has one on-board crystal:
  *