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 HDLPlanet Knowledge Capsule        Nov 2003

"Being defeated is often a temporary condition. Giving up is what makes it
                                    - Marilyn Vos Savant, US columnist, writer
Editor's note :

With OLED getting commercialized, its a significant revolution in the display
technology. Plastic being used as a glowing device, is by no means a thing to 
ignore. We needn't wonder if we soon see someone's synthetic shirt start
glowing in the night, Or even rear bumper of a car glowing at nights. But 
science/technology advancements is always paired with its evil brother, so is
there anything evil in OLEDs ? Something to wait and watch...

I. Knowledge capsule

o For the blooming professionals

  Do you know about OLED ?

  OLED - Organic Light Emitting Diode is an electronic device made by placing
  a series of organic thin films between two conductors. On applying current
  a bright light is emitted. 
  Traditional LEDs which are made using semi-conducting elements such as 
  silicon, gallium and so on with normal semiconductor production techniques. 
  On the contrary, OLEDs are made from plastic compounds originally 
  investigated for making amplifiers or switches. Light emitting effect was 
  discovered almost by accident. Since plastics are much easier to work with in
  production, OLEDs have the potential to be used in many more ways than other

  With the regular applications in mind, OLEDs have the potential to fully 
  dislodge the LCD (Liquid Crystal Display) market. Unlike LCDs, OLEDs are self
  luminous and do not require backlighting. This eliminates the need for bulky 
  and environmentally undesirable mercury lamps and yields a thinner, more 
  compact display.

  Are there any more advantages of OLEDs ?

  - One of the limitations of LCDs is its narrow viewing angle. OLEDs have a
    wide view angle (upto 160 degrees), even in bright light.

  - More power efficient. The IDTech screen claims to use 25 watts to create
    300 candela per square meter brightness. Equivalent LCDs use three times 
    as much power.
  - Greater brightness
  - Faster response time for full motion video
  - Wide viewing anlges (upto 160 degrees)
  - Greater environmental durability
  - More cost-effective
  - Broader operating temperature range
  - Lighter weight

  Are there any applications available based on this technology ?

  - Cellular Phones, Digital Video Cameras, DVD Players
  - Outdoor advertising screens
  - All LCD market segments
  - Kodak has included an OLED display in its new camera
  - Samsung has used it in its writwatch GPRS mobile phone
  - IDTech (Taiwanese Company) has announced a 20 inch monitor based on 
    this OLED Technology.

  All these announcements are significant.

o For the budding professionals

  What is Physical Design (aka BACKEND) now ??

  Think of ASIC construction as some house construction. Everyone in front end
  decides what are the rooms required in the house, how many individual rooms 
  are required, what should be the contents of individual rooms ? how every room
  is designed individually. Here house is analogous to the ASIC and the rooms 
  are analogous to individual modules of the ASIC. 

  Physical construction of the house starts later.... the engineer decides the
  placement of individual rooms within the pre-decided site (of a particular
  size). Similarly for ASICs the backend engineer decides about placement of 
  individual modules on the silicon. This could be gated by various design rules.
  One other important criteria is congestion within the chip. Congestion should
  be equally distributed across the whole chip. This process is known as 

  After the rooms and other stuff are decided to be placed at particular 
  positions on the chip, then comes the task of routing the electrical network 
  as required for all the rooms. Similarly, once the "placement" phase is over,
  interconnection routing of individual modules and spreading across the 
  electrical network forms the so called "Routing" phase.

  This is just a brief analogy for what backend means, but definitely there is 
  more depth in it and there is lot more work done in the backend phase.
  Evaluation of system timing, EMI, cross-talk, and other DSM issues are 
  undertaken in this phase of the chip design.

II. Automation Arena

 How to view a continuously growing file ?

 Some files, such as program log files or simulation transcripts keep growing 
 while the program is still running.  It is always our interest to watch what 
 is being written to the file as it's being written, but normally we're sick of 
 typing a "cat <file_name>" command every minute or two.

 The "tail <file_name>" command shows you the last 10 lines of a file.

 This saves you watching the whole file scroll past when we're only interested
 in the last few lines.

 Tail can also be used to 'follow/monitor' a file as it's being written.  In 
 this mode the last 10 lines are printed on the screen, and then extra lines 
 are printed as they're written to the file. The command is 
 "tail -f <file_name>"

 This is of great help when the completion of the job takes a long time, but 
 you are interested in looking at the intermediate steps result that is being
 dumped into the file. This "tail -f" command can be terminated by "CTRL-C".

III. Humour

"Normal people ... believe that if it ain't broke, don't fix it. Engineers
believe that if it ain't broke, it doesn't have enough features yet"                   
                                     - Scott Adams, The Dilbert Principle

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HDLPlanet Knowledge Capsule                                            Nov 2003