diff --git a/configs/Kconfig b/configs/Kconfig
index 2ad333ba2fd..94b6330f5cd 100644
--- a/configs/Kconfig
+++ b/configs/Kconfig
@@ -551,7 +551,9 @@ config ARCH_BOARD_SAMD20_XPLAINED
 	select ARCH_HAVE_BUTTONS
 	select ARCH_HAVE_IRQBUTTONS
 	---help---
-		The port of NuttX to the Atmel SAMD20-Xplained Pro development board
+		The port of NuttX to the Atmel SAMD20-Xplained Pro development board.
+		This board features the ATSAMD20J18A MCU (Cortex-M0+ with 256KB of FLASH
+		and 32KB of SRAM).
 
 config ARCH_BOARD_SAM3UEK
 	bool "Atmel SAM3U-EK development board"
diff --git a/configs/README.txt b/configs/README.txt
index ceee34cf70b..aae71edc57c 100644
--- a/configs/README.txt
+++ b/configs/README.txt
@@ -478,7 +478,9 @@ configs/sama5d3x-ek
   board, all four CPU modules, and the LCD.
 
 configs/samd20-xplained
-  The port of NuttX to the Atmel SAMD20-Xplained development board.
+  The port of NuttX to the Atmel SAMD20-Xplained Pro development board.  This
+  board features the ATSAMD20J18A MCU (Cortex-M0+ with 256KB of FLASH and
+  32KB of SRAM).
 
 configs/sam3u-ek
   The port of NuttX to the Atmel SAM3U-EK development board.