git-svn-id: svn://svn.code.sf.net/p/chibios/svn/trunk@7555 35acf78f-673a-0410-8e92-d51de3d6d3f4

1 files changed, 109 insertions, 0 deletions

diff --git a/os/hal/dox/i2c.dox b/os/hal/dox/i2c.dox
new file mode 100644
index 000000000..fb84361bc
--- /dev/null
+++ b/os/hal/dox/i2c.dox
@@ -0,0 +1,109 @@
+/*

+    ChibiOS/RT - Copyright (C) 2006,2007,2008,2009,2010,

+                 2011,2012,2013 Giovanni Di Sirio.

+

+    This file is part of ChibiOS/RT.

+

+    ChibiOS/RT is free software; you can redistribute it and/or modify

+    it under the terms of the GNU General Public License as published by

+    the Free Software Foundation; either version 3 of the License, or

+    (at your option) any later version.

+

+    ChibiOS/RT is distributed in the hope that it will be useful,

+    but WITHOUT ANY WARRANTY; without even the implied warranty of

+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

+    GNU General Public License for more details.

+

+    You should have received a copy of the GNU General Public License

+    along with this program.  If not, see <http://www.gnu.org/licenses/>.

+

+                                      ---

+

+    A special exception to the GPL can be applied should you wish to distribute

+    a combined work that includes ChibiOS/RT, without being obliged to provide

+    the source code for any proprietary components. See the file exception.txt

+    for full details of how and when the exception can be applied.

+*/

+

+/**

+ * @defgroup I2C I2C Driver

+ * @brief   Generic I2C Driver.

+ * @details This module implements a generic I2C (Inter-Integrated Circuit)

+ *          driver.

+ * @pre     In order to use the I2C driver the @p HAL_USE_I2C option

+ *          must be enabled in @p halconf.h.

+ *

+ * @section i2c_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).

+ * @if LATEX_PDF

+ * @dot

+  digraph example {

+    size="5, 7";

+    rankdir="LR";

+

+    node [shape=circle, fontname=Helvetica, fontsize=8, fixedsize="true",

+          width="0.9", height="0.9"];

+    edge [fontname=Helvetica, fontsize=8];

+

+    stop [label="I2C_STOP\nLow Power"];

+    uninit [label="I2C_UNINIT", style="bold"];

+    ready [label="I2C_READY\nClock Enabled"];

+    active_tx [label="I2C_ACTIVE_TX\nBus TX Active"];

+    active_rx [label="I2C_ACTIVE_RX\nBus RX Active"];

+    locked [label="I2C_LOCKED\nBus Locked"];

+

+    uninit -> stop [label="i2cInit()", constraint=false];

+    stop -> stop [label="i2cStop()"];

+    stop -> ready [label="i2cStart()"];

+    ready -> ready [label="i2cStart()"];

+    ready -> stop [label="i2cStop()"];

+    ready -> active_tx [label="i2cMasterTransmit()"];

+    ready -> active_rx [label="i2cMasterReceive()"];

+    active_tx -> ready [label="completed"];

+    active_rx -> ready [label="completed"];

+    active_tx -> locked [label="RDY_TIMEOUT"];

+    active_rx -> locked [label="RDY_TIMEOUT"];

+    locked -> stop [label="i2cStop()"];

+    locked -> ready [label="i2cStart()"];

+  }

+ * @else

+ * @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];

+

+    stop [label="I2C_STOP\nLow Power"];

+    uninit [label="I2C_UNINIT", style="bold"];

+    ready [label="I2C_READY\nClock Enabled"];

+    active_tx [label="I2C_ACTIVE_TX\nBus TX Active"];

+    active_rx [label="I2C_ACTIVE_RX\nBus RX Active"];

+    locked [label="I2C_LOCKED\nBus Locked"];

+

+    uninit -> stop [label="i2cInit()", constraint=false];

+    stop -> stop [label="i2cStop()"];

+    stop -> ready [label="i2cStart()"];

+    ready -> ready [label="i2cStart()"];

+    ready -> stop [label="i2cStop()"];

+    ready -> active_tx [label="i2cMasterTransmit()"];

+    ready -> active_rx [label="i2cMasterReceive()"];

+    active_tx -> ready [label="completed"];

+    active_rx -> ready [label="completed"];

+    active_tx -> locked [label="RDY_TIMEOUT"];

+    active_rx -> locked [label="RDY_TIMEOUT"];

+    locked -> stop [label="i2cStop()"];

+    locked -> ready [label="i2cStart()"];

+  }

+ * @enddot

+ * @endif

+ * The driver is not thread safe for performance reasons, if you need to access

+ * the I2C bus from multiple threads then use the @p i2cAcquireBus() and

+ * @p i2cReleaseBus() APIs in order to gain exclusive access.

+ *

+ * @ingroup IO

+ */