XArduino – A 400-MIPS co-processor for Arduino

February 7, 2010

Recently I’ve been working on XArduino which is a XMOS XS1 L1 co-processor for the Arduino open-source electronics prototyping platform.

The XArduino board provides Arduino applications with a 400 MIP’s multi-threaded 32-bit co-processor, as well as providing a VGA video output and PS/2 keyboard/mouse input for Arduino application.

It features a standard XTAG-2 to for programming and debugging. In addition the XTAG-2 interface will allow for XK-1 boards to access the VGA and PS/2 interfaces as well as way of connecting standard Arduino shields.

Note: This is a 3.3V-only board

The project is hosted at xcores.com/projects/xarduino

Creative Commons Attribution-ShareAlike 3.0 License

Xmos Development Board comparison

November 13, 2009

With all the recent Xmos development boards coming out I thought it would be a good idea to compile a comparison list. The full list is here (pdf) but a quick comparison of those boards costing less than $100 is shown below:

Feature Xmos





XS1-L1 64

Cost $99.00 $99.00** $49.95
Processor XS1-G4 XS1-L1 XS1-L1
# Pins 512 128 64
# Cores 4 1 1
Max MIPS 1600 MIPS 400 MIPS 400 MIPS
Memory – RAM 4x 64Kx8 64Kx8 64Kx8
SPI Flash 0 512Kx8 128Kx8
User I/O 60 I/O 24 I/O 32 I/O
User Interfaces USB none USB
User LED’s 12 4 2
User Switches 4 2 none
Programming I/F via USB JTAG JTAG
XSYS I/F none 2 1
Other I/F Speaker none none
Board Size 85 x 54mm 50 x 50mm 84 x 64mm


** Includes Xmos XTAG2 USB-JTAG programming adapter (costs $50)


Sparkfun XS1-L164 Development Board

November 7, 2009

Sparkfun have a new Xmos based development board. It features the powerful Xmos XS1-L1, multi-threaded processor. The processor is the XS1-L1-64 processor and is housed in a 64LQFP package and has the following features:

  • Event driven processing at 400MIPS
  • 64 kBytes of SRAM
  • 8 threads
  • 36 user I/O pins
  • 8 kBytes of OTP
  • power consumption typically 450µW/MHz

sparkfun XS1-L1-64 2

As well as the Xmos processor the SparkFun development board also features a USB interface based on FTDI FT232, external Flash EEPROM and a JTAG header. I/O is provided by 32 I/O pins brought out to pin headers next to a small prototyping area. Checking out its schematic, it looks like it can be powered form both a wall adapter and its USB port. The USB interface is to support a UART over USB and can’t be used to directly program the processor. Instead a 20-pin JTAG interface is provided. This looks to be compatible with Xmos’s own XK-1 JTAG interface and therefore Xmos new XTAG2. I’m hoping my XC-2 JTAG adapter will work with it as well.

Its competitively price at $50 or ~£30 but you still need to provide a JTAG adapter but these are available for $50. The only criticism I would make is I would liked to see the on board USB used to provide a programming (JTAG) interface as Xmos did with their XC-5 board but that said I’m hoping to get one soon and use it in my X-One console with Yvo’s VDP VGA video driver.