1 files changed, 35 insertions, 8 deletions
diff --git a/os/hal/dox/serial.dox b/os/hal/dox/serial.dox
index 071b2dac5..5b68f9c9c 100644
--- a/os/hal/dox/serial.dox
+++ b/os/hal/dox/serial.dox
@@ -1,5 +1,6 @@
 /*
-    ChibiOS/RT - Copyright (C) 2006,2007,2008,2009,2010 Giovanni Di Sirio.
+    ChibiOS/RT - Copyright (C) 2006,2007,2008,2009,2010,
+                 2011 Giovanni Di Sirio.
 
     This file is part of ChibiOS/RT.
 
@@ -19,16 +20,42 @@
 
 /**
  * @defgroup SERIAL Serial Driver
- * @brief Generic Serial Driver.
+ * @brief   Generic Serial Driver.
  * @details This module implements a generic full duplex serial driver. The
- * driver implements a @p SerialDriver interface and uses I/O Queues for
- * communication between the upper and the lower driver. Event flags are used
- * to notify the application about incoming data, outgoing data and other I/O
- * events.<br>
- * The  module also contains functions that make the implementation of the
- * interrupt service routines much easier.
+ *          driver implements a @p SerialDriver interface and uses I/O Queues
+ *          for communication between the upper and the lower driver. Event
+ *          flags are used to notify the application about incoming data,
+ *          outgoing data and other I/O events.<br>
+ *          The  module also contains functions that make the implementation
+ *          of the interrupt service routines much easier.
  * @pre     In order to use the SERIAL driver the @p HAL_USE_SERIAL option
  *          must be enabled in @p halconf.h.
  *
+ *
+ * @section serial_1 Driver State Machine
+ * The driver implements a state machine internally, not all the driver
+ * functionalities can be used in any moment, any transition not explicitly
+ * shown in the following diagram has to be considered an error and shall
+ * be captured by an assertion (if enabled).
+ * @dot
+  digraph example {
+    rankdir="LR";
+    node [shape=circle, fontname=Helvetica, fontsize=8, fixedsize="true",
+          width="0.9", height="0.9"];
+    edge [fontname=Helvetica, fontsize=8];
+
+    uninit [label="SD_UNINIT", style="bold"];
+    stop [label="SD_STOP\nLow Power"];
+    ready [label="SD_READY\nClock Enabled"];
+
+    uninit -> stop [label=" sdInit()"];
+    stop -> stop [label="\nsdStop()"];
+    stop -> ready [label="\nsdStart()"];
+    ready -> stop [label="\nsdStop()"];
+    ready -> ready [label="\nsdStart()"];
+    ready -> ready [label="\nAny I/O operation"];
+  }
+ * @enddot
+ *
  * @ingroup IO
  */