dengweijie/lib_xua
1
0
Fork 0
forked from PAWPAW-Mirror/lib_xua
Code Pull Requests Activity

Update AN00246_xua_example.rst

Browse Source
This commit is contained in:
Ross Owen
2022-08-09 11:25:03 +01:00
committed by GitHub
parent aea1e97d9d
commit b7f9dd5781
1 changed files with 22 additions and 32 deletions
Download Patch File Download Diff File Expand all files Collapse all files

54
examples/AN00246_xua_example/doc/rst/AN00246_xua_example.rst
View File

@@ -48,7 +48,7 @@ be included in your code to use the library.
:start-on: include "xua.h"
:end-on: include "xud_device.h"
Allocating hardware resources
Allocating Hardware Resources
.............................
A basic implementation of a USB Audio device (i.e. simple stereo output via I2S)
@@ -63,7 +63,7 @@ using ``lib_xua`` requires the follow pins:
This application note assumes xCORE is I2S bus master
On an xCORE the pins are controlled by ``ports``. The application therefore declares various ``ports``
In the xCORE architecture the I/O pins are controlled and accessed by ``ports``. The application therefore declares various ``ports``
for this purpose:
.. literalinclude:: app_xua_simple.xc
@@ -71,8 +71,8 @@ for this purpose:
:end-on: in port p_mclk_in
``lib_xua`` also requires two ports for internally calculating USB feedback. Please refer to
the ``lib_xua`` library documentation for further details. The additonal input port for the master
clock is required since USB and S/PDIF do not reside of the same tiles on the example hardware.
the ``lib_xua`` library documentation for further details. The additional input port for the master
clock is required since USB and S/PDIF do not reside of the same tiles on the xCORE.ai MC Audio Board.
These ports are declared as follows:
@@ -90,7 +90,7 @@ Again, for the same reasoning as the master-clock ports, two master-clock clock-
- one on each tile.
Other declarations
Other Declarations
..................
``lib_xua`` currently requires the manual declaration of tables for the endpoint types for
@@ -107,12 +107,12 @@ These are declared as follows:
:start-on: /* Endpoint type tables
:end-on: XUD_EpType epTypeTableIn
The application main() function
The Application main() Function
-------------------------------
The ``main()`` function sets up the tasks in the application.
Various channels are required in order to allow the required tasks to communcate.
Various channels are required in order to allow the required tasks to communicate.
These must first be declared:
.. literalinclude:: app_xua_simple.xc
@@ -129,6 +129,9 @@ using the xC ``par`` construct:
This code starts the low-level USB task, an Endpoint 0 task, an Audio buffering task and a task to handle
the audio I/O (i.e. I2S signalling).
It also runs a small function ``ctrlPort()`` that simply writes some values to an I/O port to configure some external
hardware (it enables analogue power supplies and correctly routes the master clock) and then closes.
Configuration
.............
@@ -157,10 +160,10 @@ implentation e.g. master clock frequencies and must be defined. Please see the
Demo Hardware Setup
-------------------
To run the demo, use a USB cable to connect the on-board xTAG debug adapter (marked DEBUG) to your development computer.
Use another USB cable to connect the USB receptacle marked USB DEVICE to the device you wish to play audio from.
To run the demo, use a USB cable to connect the on-board xTAG debug adapter (marked ``DEBUG``) to your development computer.
Use another USB cable to connect the USB receptacle marked ``USB DEVICE`` to the device you wish to play audio from.
Plug a device capable of receiving analogue audio (i.e. a amplified speaker) to the 3.5mm jack marked OUT 1/2.
Plug a device capable of receiving analogue audio (i.e. an amplified speaker) to the 3.5mm jack marked ``OUT 1/2``.
.. figure:: images/hw_setup.*
:width: 80%
@@ -169,40 +172,27 @@ Plug a device capable of receiving analogue audio (i.e. a amplified speaker) to
|newpage|
Launching the demo application
Launching the Demo Application
------------------------------
Once the demo example has been built either from the command line using xmake or
via the build mechanism of xTIMEcomposer studio it can be executed on the xCORE.ai
MC Audio board.
Once the demo example has been built from the command line using ``xmake``
it can be executed on the xCORE.ai MC Audio Board.
Once built there will be a ``bin/`` directory within the project which contains
the binary for the xCORE device. The xCORE binary has a XMOS standard .xe extension.
Launching from the command line
Launching from the Command Line
...............................
From the command line you use the ``xrun`` tool to download and run the code
on the xCORE device::
xrun --xscope bin/app_xua_simple.xe
xrun ./bin/app_xua_simple.xe
Once this command has executed the application will be running on the
xCORE.ai MC Audio Board
Launching from xTIMEcomposer Studio
...................................
From xTIMEcomposer Studio use the run mechanism to download code to xCORE device.
Select the xCORE binary from the ``bin/`` directory, right click and go to Run
Configurations. Double click on xCORE application to create a new run configuration,
enable the xSCOPE I/O mode in the dialog box and then
select Run.
Once this command has executed the application will be running on the
xCORE.ai MC Audio board.
Running the application
Running the Application
.......................
Once running the device will be detected as a USB Audio device - note, Windows operating
@@ -233,11 +223,11 @@ References
|newpage|
Full source code listing
Full Source Code Listing
------------------------
Source code for main.xc
.......................
Source Code for app_xua_simple.xc
.................................
.. literalinclude:: app_xua_simple.xc
:largelisting: