XMOS XK XS1-G User manual
XK XS1-G Development System Quick Start Guide (1.1) 2/9
1 Introduction
The XDK XS1-G Development System contains everything you need to start exploring
the XMOS event-driven processor technology.
The XDK Development System includes:
•
XS1-G Development Kit (XDK)—the black box with all the electronics and hard-
ware.
•12V power supply unit and local AC power cable.
•USB cable—connects your system to the XDK.
•
XMOS Link cable (x 2)—connects the XDK to other devices using XMOS Link
sockets. XMOS Link cables have the same form factor as Ethernet cables, but are
crossover cables that can only be used for linking to XDK XMOS Link sockets.
2 XDK Demos
A set of demonstrations is pre-installed on the XDK which you can use to test the
hardware. Additional demonstrations can be downloaded from the XMOS web site,
including an XDK tutorial which introduces the key concepts you need to understand
when programming the XK-1 board.
1. Plug in the XDK using the supplied power cable.
2.
Slide the
ON/OFF
button (below the power socket) up to switch the XDK on
and wait for the splash screen to be displayed.
3. Press the MENU (black/middle) button to go to the Menu page.
4.
Press the
UP
(red/left) and
DOWN
(green/right) buttons to scroll through the
demos.
5.
Highlight the Pong demo (PONG.XB) and press the
RUN
(blue) button to play
the demo.
6. Press MENU to go back to the Menu screen.
www.xmos.com
XK XS1-G Development System Quick Start Guide (1.1) 4/9
2.1 Pong (PONG)
Pong is a simple application that uses four threads. The state machine polls the but-
ton thread to see if a button is currently pressed, makes the main game calculations,
updates the positions of the pads and ball and passes them to the frame generator.
The frame generator draws the raw pixel data, and passes it through a channel to
the LCD driver thread to output to the screen.
The demonstration is divided across four XCores due to the device mapping on the
XDK.
Use the two left buttons to move the left paddle up and down, and the two right
buttons to move the right paddle.
Button
Reader
Frame
Generator
LCD
Driver
LCD
XCORE0 XCORE3
XCORE2XCORE1
Is a button pressed?
Pixel data
Buttons
5 Mhz RGB Bus
Pong
State
Machine
www.xmos.com
XK XS1-G Development System Quick Start Guide (1.1) 5/9
2.2 Mandelbrot (MBROT)
The Mandelbrot demonstration uses the concurrent feature of the XMOS architecture
to farm out the processing to multiple threads running across the XCores.
The generation manager requests Mandelbrot calculations from eight threads running
the escape time algorithm. It then passes the resulting pixel data to the SRAM server
for storage.
Concurrently, the SRAM server pipes the RGB data to the LCD driver, which displays
the image on the LCD.
SRAM Server
SRAM
Server
M-brot
processor
LCD
Driver
LCD
XCORE0 XCORE3
XCORE2
XCORE1
5 Mhz RGB Bus
M-brot
processor
M-brot
processor
M-brot
processor
M-brot
processor
M-brot
processor
M-brot
processor
M-brot
processor
Mandelbrot
generation
manager
www.xmos.com
XK XS1-G Development System Quick Start Guide (1.1) 6/9
2.3 Audio Frequency Analyser (FREQ)
The FREQ program reads audio input, and visualizes the power in each frequency
band in real-time on the screen. Connect a microphone or MP3 player to the line
input to run the program.
The horizontal axis of the screen is time, and the vertical axis represents the
frequency bands. The sound intensity is represented by colorâ˘
Aˇ
Tdark colors indicate
little power in the band, and bright colors indicate high power. The power spectrum
is updated in real-time using a sliding window, which represents about a second
worth of audio.
Internally, the program computes a 512-sample FFT, and uses a lookup table to map
the magnitude of each frequency onto a color. The FFT is computed 200 times per
second with a 75% overlap—128 new samples are appended to 384 of the previous
samples and the FFT is computed over these 512 samples. The real and imaginary
components are squared and summed, the sine and cosine parts are then added,
and the resulting value is used to lookup a color.
Buffer
Codec
Client
LCD
Driver
FFT
DAC
ADC
Audio
Buffer
LCD
XCORE0
XCORE3
XCORE2XCORE1
www.xmos.com
XK XS1-G Development System Quick Start Guide (1.1) 7/9
2.4 Touch Screen Finger Follow
The touch-screen demonstration has the following behavior:
When the application starts, a large red cross is displayed on the LCD screen. When
a press is detected, the color of the cross is changed to green, and the cross follows
the user’s finger. On release, the color of the cross returns to red.
To achieve this functionality the application is broken down to three threads:
1. Position Keeper
: Effectively this thread allows state to be safely shared between
the LCD driver thread and the main program loop. This thread stores the color
and position of the cross. It takes updates to this shared state from the main
program loop and responds to requests for data from the LCD driver.
2. Main program loop
: This thread is paused waiting for the PENIRQ line from
the touch screen digitizer to go low, indicating the screen is pressed. When
this event is fired, it sends a command (via a channel) to the position keeper to
update the color of the cross, then reads the position on the press and issues
another command to the position keeper to update the location of the cross.
This thread also lights associated core LEDs dependent on the position read.
Once done the color of the displayed cross is reset to red.
3. LCD Driver
: This thread is responsible for providing the physical interface to
the screen. It requests an update for the position/color of the cross once per
frame. This thread uses timers to produce the appropriate control signal and
horizontal/vertical blanking delays.
LCD
ADC
XCORE3
Position
keeper
LCD Driver
Main loop
(reads ADC)
update position
request position
position data
www.xmos.com
XK XS1-G Development System Quick Start Guide (1.1) 8/9
2.5 Menu system, loader and LCD screen (XDK)
The XDK menu program is provided for users who want to change the menu for their
own use. If you run XDK.XB, the XDK will appear to reset itself, as it re-runs the
menu; no other behavior is expected.
The program uses SRAM, LCD, and SD/FAT16 files system software components to
display the menu system.
The program uses the SD/FAT16 component to load images from the SD card into
frame buffers in the SRAM.
The LCD component includes a thread, which reads frame data from the SRAM and
buffers it locally. A character buffer thread calculates pixel values using a local
character buffer. For each pixel in a frame, these two threads output data through
a channel to a blender thread that does a simple blending operation. The blender
thread outputs the blended pixel data to the LCD server thread, which provides the
interface to the LCD.
The main menu program thread uses two channels to communicate with the LCD
component, one for text and the other for graphics. The text channel adds characters
to, and removes them from, the character buffer. The graphics channel is used for
frame update commands and other system requirements.
Buttons
SD Card SRAM
SD/FAT
Server
SRAM
Server
Menu
Program
RGB
Driver
Blend
LCD
Server
Char
Buffer
SRAM
Buffer
LCD
RGB LEDs
XCORE0
XCORE3
XCORE1 XCORE2
FIFO
www.xmos.com
XK XS1-G Development System Quick Start Guide (1.1) 9/9
3 XMOS Tools Support
The XMOS tools are provide in a single platform-specific downloadable file from
http://www.xmos.com/tools
Instructions on installing and using the XMOS Tools can be found in the XMOS
Tools User Guide
http://www.xmos.com/published/xtools_en
. The following table
provides a summary tools support for the XDK.
Minimum tools version required 9.7
Board support file XDK.xn
USB-to-JTAG adaptor Internal
USB-to-JTAG driver FTDI
Board Tutorial Integrated into XDE and available as PDF
4 Document History
Date Release Comment
2009-07-08 1.0 First release
2010-05-10 1.1 Added tools support section
Disclaimer
XMOS Ltd. is the owner or licensee of this design, code, or Information (collectively, the
“Information”) and is providing it to you “AS IS” with no warranty of any kind, express or
implied and shall have no liability in relation to its use. XMOS Ltd. makes no representation
that the Information, or any particular implementation thereof, is or will be free from any
claims of infringement and again, shall have no liability in relation to any such claims.
Copyright
©
2010 XMOS Ltd. All Rights Reserved. XMOS and the XMOS logo are registered
trademarks of XMOS Ltd in the United Kingdom and other countries, and may not be used
without written permission. Company and product names mentioned in this document are the
trademarks or registered trademarks of their respective owners. Where those designations
appear in this document, and XMOS was aware of a trademark claim, the designations have
been printed with initial capital letters or in all capitals.
www.xmos.com
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