diff --git a/configs/stm3210e-eval/README.txt b/configs/stm3210e-eval/README.txt
index b63f7c5f293..e8d634bb985 100755
--- a/configs/stm3210e-eval/README.txt
+++ b/configs/stm3210e-eval/README.txt
@@ -263,7 +263,7 @@ More complex temperature sensor operations are also available.  See the IOCTAL
 commands enumerated in include/nuttx/sensors/lm75.h.  Also read the descriptions
 of the stm32_lm75initialize() and stm32_lm75attach() interfaces in the
 arch/board/board.h file (sames as configs/stm3210e-eval/include/board.h).
- 
+
 STM3210E-EVAL-specific Configuration Options
 ============================================
 
@@ -596,6 +596,38 @@ Where <subdir> is one of the following:
 
     CONFIG_STM32_BUILDROOT=y	  : NuttX buildroot under Linux or Cygwin
 
+    USB debug output can be enabled as by changing the following
+    settings in the configuration file:
+
+    -CONFIG_DEBUG=n
+    -CONFIG_DEBUG_VERBOSE=n
+    -CONFIG_DEBUG_USB=n
+    +CONFIG_DEBUG=y
+    +CONFIG_DEBUG_VERBOSE=y
+    +CONFIG_DEBUG_USB=y
+
+    -CONFIG_EXAMPLES_USBSERIAL_TRACEINIT=n
+    -CONFIG_EXAMPLES_USBSERIAL_TRACECLASS=n
+    -CONFIG_EXAMPLES_USBSERIAL_TRACETRANSFERS=n
+    -CONFIG_EXAMPLES_USBSERIAL_TRACECONTROLLER=n
+    -CONFIG_EXAMPLES_USBSERIAL_TRACEINTERRUPTS=n
+    +CONFIG_EXAMPLES_USBSERIAL_TRACEINIT=y
+    +CONFIG_EXAMPLES_USBSERIAL_TRACECLASS=y
+    +CONFIG_EXAMPLES_USBSERIAL_TRACETRANSFERS=y
+    +CONFIG_EXAMPLES_USBSERIAL_TRACECONTROLLER=y
+    +CONFIG_EXAMPLES_USBSERIAL_TRACEINTERRUPTS=y
+
+    By default, the usbserial example uses the Prolific PL2303
+    serial/USB converter emulation.  The example can be modified
+    to use the CDC/ACM serial class by making the following changes
+    to the configuration file:
+
+    -CONFIG_USBSER=y
+    +CONFIG_USBSER=n
+
+    -CONFIG_CDCSER=n
+    +CONFIG_CDCSER=y
+
   usbstorage:
   ----------
     This configuration directory exercises the USB mass storage
diff --git a/configs/stm3210e-eval/usbserial/defconfig b/configs/stm3210e-eval/usbserial/defconfig
index cb4d9fb4cb0..ec48e44c9f1 100755
--- a/configs/stm3210e-eval/usbserial/defconfig
+++ b/configs/stm3210e-eval/usbserial/defconfig
@@ -674,7 +674,7 @@ CONFIG_USBSER_TXBUFSIZE=512
 # CONFIG_CDCSER
 #   Enable compilation of the USB serial driver
 # CONFIG_CDCSER_EP0MAXPACKET
-#   Endpoint 0 max packet size. Default 8.
+#   Endpoint 0 max packet size. Default 64
 # CONFIG_CDCSER_EPINTIN
 #   The logical 7-bit address of a hardware endpoint that supports
 #   interrupt IN operation.  Default 2.
@@ -683,7 +683,7 @@ CONFIG_USBSER_TXBUFSIZE=512
 #   Default 64.
 # CONFIG_CDCSER_EPINTIN_HSSIZE
 #   Max package size for the interrupt IN endpoint if high speed mode.
-#   Default 512.
+#   Default 64
 # CONFIG_CDCSER_EPBULKOUT
 #   The logical 7-bit address of a hardware endpoint that supports
 #   bulk OUT operation