Wednesday, January 18, 2017

Xilinx Vivado

My first project

Friday, November 25, 2016

How to switch GCC version on Ububtu

I had installed GCC version 4.9 and 5.4 from the Ubuntu repositories. How to switch GCC version?
You can switch the symlinks yourself manually, but using "update-alternatives" makes it easy.

[ ]$ sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-4.9 100 --slave /usr/bin/g++ g++ /usr/bin/g++-4.9
[ ]$ sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-5 50 --slave /usr/bin/g++ g++ /usr/bin/g++-5 

Now you can switch between these versions by using:

[ ]$ sudo update-alternatives --config gcc

Tuesday, October 18, 2016

The 2 Good Books

System on Chip Interfaces for Low Power Design (PDF)

Paperback: 406 pages
Publisher: Morgan Kaufmann; 1 edition (December 22, 2015)
Language: English
ISBN-10: 0128016302
ISBN-13: 978-0128016305

Digital Design and Computer Architecture. ARM Edition (PDF)

Paperback: 584 pages
Publisher: Morgan Kaufmann; 1 edition (May 6, 2015)
Language: English
ISBN-10: 0128000562
ISBN-13: 978-0128000564

Saturday, July 30, 2016

Cortex-M on Mac OS

Build Toolchain

Copy the src release package into ~/mac-build/ directory
$ cp gcc-arm-none-eabi-5_3-2016q1-20160330-src.tar.bz2 ~/mac-build 

Prepare source codes
$ cd ~/mac-build
$ tar xjf gcc-arm-none-eabi-5_3-2016q1-20160330-src.tar.bz2
$ cd ./gcc-arm-none-eabi-5_3-2016q1-20160330/src
$ find . -name '*.tar.*' | xargs -I% tar -xf %
$ cd ..
  • Build the toolchain
Start building the toolchain.
$ ./
$ ./

Cortex-M Platform


Sunday, January 3, 2016

逝去的 2015

Po 文驟減的一年、沒了閒情逸致。庸庸碌碌的 2015 ...

Saturday, August 22, 2015

HOWTO compile Android in Ubuntu 14.04.1 LTS

Tuesday, May 12, 2015

MediaTek Helio(TM) X20

MediaTek Helio(TM) X20: The World's First Mobile SoC Featuring Tri-Cluster(TM) CPU Architecture

MediaTek today announces the launch of the MediaTek Helio™ X20 -- the world's first mobile processor with Tri-Cluster™ CPU architecture and ten processing cores (Deca-core). The Helio X20 continues MediaTek's mission of delivering industry-leading computing performance coupled with unmatched power efficiency. With the integration of MediaTek's WorldMode Category 6 LTE modem with carrier aggregation and upgraded CorePilot® 3.0 advanced scheduling algorithm, the Helio X20 is set to revolutionize the mobile processor industry and address the global demand for flagship mobile devices. The Helio X20 is expected to be available in consumer products by end of this year. 

Today's mobile devices are being asked to perform a wider range of tasks than ever before. Gaming requires sustained high-performance, advanced imaging and video recording need bursts of peak processor power, which are heavy load tasks. These are coupled with lighter load tasks, such as Internet browsing and audio. Battery life is also of paramount importance to all types of users. Yet existing mobile processing architectures don't efficiently meet the wide spectrum of use case scenarios. Currently, most high-end smartphones use dual cluster architectures, which limit the extent of the lowest power at one end and the computing granularity across the different configurations. 

MediaTek's Tri-Cluster CPU architecture in the Helio X20 provides three processor clusters, each designed to more efficiently handle different types of workloads. The Tri-Cluster CPU consists of one cluster of two ARM Cortex-A72 cores (running at 2.5GHz for extreme performance) and two clusters of four ARM Cortex-A53 cores (one running at 2.0GHz for medium loads and one running at 1.4GHz for light activities). Much like adding gears to vehicles, dividing the cores into three clusters provides a more efficient allocation of tasks for optimum performance and extended battery life. 

The Tri-Cluster CPU architecture is enabled by MediaTek's new CorePilot 3.0 heterogeneous computing scheduling algorithm. CorePilot 3.0 schedules the tasks for all CPUs and GPUs on the SoC while managing power and thermal effects so that extreme performance can be attained while creating less heat. It provides up to a 30% reduction of power consumption compared with conventional dual cluster architectures. 

 "By leading with mobile CPU architecture and multimedia innovation, MediaTek continues to push the envelope of power efficiency and peak performance," said Jeffrey Ju, Senior Vice President of MediaTek. "We are excited to see device manufacturers raise the bar -- in camera, display, audio and other consumer features. MediaTek has been adding innovative multimedia features to our platforms since the very beginning, enhancing the overall computing and multimedia experience as part of our strategy to put leading technology into the hands of everyone."

PR Newswire