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Some miscellenous questions

Started by vorange October 19, 2007
1) How does one (cheaply) mount a BGA chip of say 217 pins?  I'm
getting fustrated as there are chips that I want to use but
manufacturers are shipping them out in BGA format only.  I speak
specifically of the SAM9 series from Atmel.  I know they have the 9260
in lqfp format but what is the point of claiming its 'pin compatible'
when they are not even releasing lqfp package for the newer chips?

2) Do you guys use other ARM9s and if so from which vendor?

3) What really is the use of an on-chip lcd controller that some of
these arm9s have if every tft lcd is so different in terms of
pinouts..etc from one to the next?  Do I really even need an lcd
controller on-chip to drive a tft?

4) Can you suggest any tft lcds where the manufacturer does not pull a
vanishing act with its product (out of production) every now and
then?  What is a good place to buy tft LCDs?

5) I notice there are embedded boards which can boot windows CE or
linux.  How exactly does the board manufacturer get the lcd to display
the output onto the screen?  Does he have to use a specific Lcd that
is supported by say linux (which has a driver available)?  I'm a bit
unclear about the process.  If I wanted to use Atmel's SAM9 series,
how would i integrate an LCD to display the command line of linux onto
there or the gui of windows ce?

Thank you for your answers

"vorange" <orangepic@yahoo.com> wrote in message 
news:1192774388.943776.14350@e34g2000pro.googlegroups.com...
> 1) How does one (cheaply) mount a BGA chip of say 217 pins? I'm > getting fustrated as there are chips that I want to use but > manufacturers are shipping them out in BGA format only. I speak > specifically of the SAM9 series from Atmel. I know they have the 9260 > in lqfp format but what is the point of claiming its 'pin compatible' > when they are not even releasing lqfp package for the newer chips?
You really need a reflow oven. Some folk have reported success by modifying a toaster oven if you want cheap but it's not terribly professional in a production environment.
> 2) Do you guys use other ARM9s and if so from which vendor?
I've heard of people having good success with the Sharp (now NXP) ARM9 microcontrollers.
> 3) What really is the use of an on-chip lcd controller that some of > these arm9s have if every tft lcd is so different in terms of > pinouts..etc from one to the next? Do I really even need an lcd > controller on-chip to drive a tft?
They're not all that different in the signals required even if they have a variety of pinouts. The important thing is that the LCD controller is flexible enough to drive a range of screens. You don't need a controller on-chip and there are many capable external devices available but benefits of a reducing the number of parts on the board often favour an all-in-one solution.
> 4) Can you suggest any tft lcds where the manufacturer does not pull a > vanishing act with its product (out of production) every now and > then? What is a good place to buy tft LCDs?
Sharp, Hitachi and Toshiba have good lifespans on their industrial screens. Other firms concentrate on the laptop market and can be more volatile. Personally, I chose a screen from the laptop market because it was cheap but it is pin (and driver) compatible with a Sharp screen in case the laptop ones disappear suddenly. It doesn't have the same mountings but I'm fortunate in that I can be flexible with the mechanical design.
> 5) I notice there are embedded boards which can boot windows CE or > linux. How exactly does the board manufacturer get the lcd to display > the output onto the screen? Does he have to use a specific Lcd that > is supported by say linux (which has a driver available)? I'm a bit > unclear about the process. If I wanted to use Atmel's SAM9 series, > how would i integrate an LCD to display the command line of linux onto > there or the gui of windows ce?
You'll need a driver. Some drivers will do different screens and some are specific to one brand. Or you can write one.