1 files changed, 67 insertions, 0 deletions
diff --git a/c-user/regulator/operations.rst b/c-user/regulator/operations.rst
new file mode 100644
index 0000000..a9e5a44
--- /dev/null
+++ b/c-user/regulator/operations.rst
@@ -0,0 +1,67 @@
+.. SPDX-License-Identifier: CC-BY-SA-4.0
+
+.. Copyright (C) 2023 On-Line Applications Research Corporation (OAR)
+
+.. _RegulatorManagerOperations:
+
+Operations
+==========
+
+Application Sourcing Data
+-------------------------
+
+The application interacting with the Source will obtain buffers from
+the regulator instance, fill them with information, and send them to
+the regulator instance. This allows the regulator to buffer bursty input.
+
+A regulator instance is used as follows from the Source side:
+
+.. code-block:: c
+
+    while (1) {
+      use rtems_regulator_obtain_buffer to obtain a buffer
+      // Perform some input operation to fetch data into the buffer
+      rtems_regulator_send(buffer, size of message)
+    }
+
+The delivery of message buffers to the Destination and subsequent release is
+performed in the context of the delivery thread by either the delivery
+function or delivery thread. Details are below.
+
+The sequence diagram below shows the interaction between a message Source,
+a Regulator instance, and RTEMS, given the usage described in the above
+paragraphs.
+
+.. _fig-regulator_input_sequence:
+
+.. figure:: ../../images/c_user/regulator_input_sequence.png
+   :width: 90%
+   :alt: Regulator Application Input Source Usage
+   :figclass: align-center
+
+As illustrated in the preceding sequence diagram, the Source usually
+corresponds to application software reading a system input. The Source
+obtains a buffer from the Regulator instance and fills it with incoming
+data.  The application explicitly obtaining a buffer and filling it in
+allows for zero copy operations on the Source side.
+
+After the Source has sent the message to the Regulator instance,
+the Source is free to process another input and the Regulator
+instance will ensure that the buffer is delivered to the Delivery
+function and Destination.
+
+Delivery Function
+-----------------
+The Delivery function is provided by the application for a specific
+Regulator instance. Depending on the Destination, it may use a function which
+copies the buffer contents (e.g., write()) or which operates directly
+on the buffer contents (e.g. DMA from buffer). In the case of a 
+Destination which copies the buffer contents, the buffer can be released
+via  :ref:`InterfaceRtemsRegulatorReleaseBuffer`  as soon as the function
+or copying completes. In the case where the delivery uses the buffer
+and returns, the call to :ref:`InterfaceRtemsRegulatorReleaseBuffer`
+will occur when the use of the buffer is complete (e.g. completion
+of DMA transfer).  This explicit and deliberate exposure of buffering
+provides the application with the ability to avoid copying the contents.
+
+