In gvim, how can I set or change font size and type?

If you use vim, copy .vimrc to .gvimrc
1. cp .vimrc .gvimrc
2. open .gvimrc
3. add
 set fgn=Monospace\ Regular\ 12

After executing gvim, you can find changed font type and size.

http://www.troubleshooters.com/linux/vifont.htm

How to capture TCP dump in iPhone?

1. Need a Mac PC.
2. Install Xcode in the Mac
 - check UDID
 - execute rvictl command
3. Run Xcode > Window > Devices
 iPhone > Identifier
4. Run Terminal
 $ rvictl -s

 # start capturing TCP dump
 $ sudo tcpdump -i rvi0 -w trace.pcap

 # stop capturing TCP dump
 $ rvictl -x

* Reference
https://developer.apple.com/library/mac/qa/qa1176/_index.html
http://useyourloaf.com/blog/2012/02/07/remote-packet-capture-for-ios-devices.html

Android sleep

1. Wake up
write on /sys/power/state
2. Sleep
write mem /sys/power/state

Why mem?
I think mem means that suspend to RAM (memory).

From the Linux Document
https://www.kernel.org/doc/Documentation/ABI/testing/sysfs-power
and https://www.kernel.org/doc/Documentation/power/states.txt

How to study C# language

1. read the C# specification: "CSharp Language Specification.docx"
 - In the Microsoft web site, search "C# specification"
 - Download & read it

2. Inside C#

3. C# in Depth

& ...

HVT, LVT

http://www.edaboard.com/thread135577.html

HVT - High V threshold. Can be used in the path where timing is not critical. So by using HVT cells we can save power.
LVT - Low V threshold. One should use these cells in timing critical paths. These cells are fast but , comsumes more power due to its leakage. So it will consume more power. So use only when timing is critical.
SVT - Standard V threshold. Best of both world. Medium delay and medium power requirment. So if timing is not met by small magin with HVT, you should try with SVT. And at last LVT.

Do you know PS HOLD, PS_HOLD, PSHOLD?

PS HOLD stands for Power Supply HOLD in processor.

From the st document you can find the word.
 "For a successful startup, the PSHOLD (power supply hold) needs to be pulled high within specific time, tON_BLANK"
http://www.st.com/web/en/resource/technical/document/datasheet/CD00226957.pdf