Various documentation improvements.

git-svn-id: svn://svn.code.sf.net/p/chibios/svn/trunk@2788 35acf78f-673a-0410-8e92-d51de3d6d3f4

1 files changed, 19 insertions, 12 deletions

diff --git a/os/hal/dox/usb.dox b/os/hal/dox/usb.dox
index 568272e13..af34e1abd 100644
--- a/os/hal/dox/usb.dox
+++ b/os/hal/dox/usb.dox
@@ -206,21 +206,28 @@
  *   @enddot

  *   <br><br>

  * .

- * An important difference in the two modes is that there is a dedicated

- * endpoint buffer in packet mode while in transaction mode the application

- * specifies its own buffer for the whole transfer.

+ * @subsection usb_2_3 USB Packet Buffers

+ * An important difference between packet and transaction modes is that there

+ * is a dedicated endpoint buffer in packet mode while in transaction mode

+ * the application has to specify its own buffer for duration of the whole

+ * transfer.<br>

+ * Packet buffers cannot be accessed directly by the application because those

+ * could not be necessarily memory mapped, a buffer could be a FIFO or some

+ * other kind of memory accessible in a special way depending on the

+ * underlying hardware architecture, the functions @p usbReadPacketI() and

+ * @p usbWritePacketI() allow to access packet buffers in an abstract way.

  *

- * @subsection usb_2_3 USB Callbacks

+ * @subsection usb_2_4 USB Callbacks

  * The USB driver uses callbacks in order to interact with the application.

- * There are several kind of callbacks to be handled:

- * - Driver-wide events callback. As example errors, suspend event, reset

- *   event etc.

- * - Messages hook callback. This hook allows the application to implement

+ * There are several kinds of callbacks to be handled:

+ * - Driver events callback. As example errors, suspend event, reset event

+ *   etc.

+ * - Messages Hook callback. This hook allows the application to implement

  *   handling of custom messages or to override the default handling of

- *   standard messages.

- * - Descriptor requested callback. When the driver endpoint zero handler

- *   needs to serve a descriptor to the host it queries the application

- *   using this callback.

+ *   standard messages on endpoint zero.

+ * - Descriptor Requested callback. When the driver endpoint zero handler

+ *   receives a GET DESCRIPTOR message and needs to send a descriptor to

+ *   the host it queries the application using this callback.

  * - Start of Frame callback. This callback is invoked each time a SOF

  *   packet is received.

  * - Endpoint callbacks. Each endpoint informs the application about I/O