The Investors' Relations pages on the ARM website show some interesting information:stevech:
ARM’s web site implores people to not use ARM7 in any new designs.…
…
But there are still a lot of ARM7 boards for sale, ready to use.
The breakdown of ARM unit shipments in 2009 is shown on Page 6 of the ARM Annual financial report:
ARM7 55%
ARM9 39%
ARM11 5%
Cortex 1%
The most recent figures (Q3 2010) show that this ratio is now:
ARM7 49%
ARM9 33%
ARM11 9%
Cortex 9%
ARM 7 is the oldest and furthermore has the biggest support, ppl have used it and they can help me to use it as well. If I would buy a newer processor I don’t think I would get that much help.
Also, leon I have applied to ur group please accept me. Also U haven’t commented on my board is it any good?
edit: I just joined the lpc yahoo group and on the files section there is only 1 design file which is a rar containing unknown files extensions.
It looks like you are connecting the caps in series between the Vdd and the uC pins. They should be in parallel. You can however connect them all together, as long as there are caps sufficiently close.
Where is the crystal?
I may have been mistaken about the pullups on the JTAG, but I am very sure that you need them on /RESET and P0.14.
I won’t say that this project is impossible at your experience level, because I designed my first ARM7 circuit without much knowledge either, but it’s gonna be hard.
There are several PCB designs in the LPC2000 group files section. You should get plenty of ideas from them. Also look at commercial boards like those from Olimex. The PCB layouts aren’t available but you should be able to copy the schematic and the component placements.
You use WinRAR to uncompress .rar files!
The latest effort has just as many problems as previous ones. Why don’t you put the decoupling capacitors close to the chip? Putting them on the underside might help.
if I put them closer than the wires for the other pins would have no space and overlap… But if you consider that the processor has 6mmx6mm dimensions it isn’t that far…
I know it is a rar but inside the rar there are some strange files extensions like .gtp
would you mind to tell me which specific files to download? Coz I cant find them…
tried my best, I haven’t added the crystal yet, because I don’t know where and how to connect it. On eagle library the crystal has 4 pins I thought it only had 2 pins… anyways, if anyone has any lbr file or can tell me how to connect them I would appreciate it… I have finished!!! I think… The wires overlap and overall its a really bad board any ideas? What to fix? and what to add?
Any suggestions?
d4n1s:
tried my best, I haven’t added the crystal yet, because I don’t know where and how to connect it. On eagle library the crystal has 4 pins I thought it only had 2 pins… anyways, if anyone has any lbr file or can tell me how to connect them I would appreciate it… I have finished!!! I think… The wires overlap and overall its a really bad board any ideas? What to fix? and what to add?Any suggestions?
Crystals come in 2 and 4 pin packages, but the 4 pin packages generally have 2 pins which don’t need to be connected.
Place the decoupling capacitors and crystal next to the chip and route the critical nets (supply, ground and clock) first. Then route the other nets.
This is how you use decoupling capacitors.
http://www.cvel.clemson.edu/emc/tutoria … ing01.html
Don’t forget the PLL.
Seriously, move to an easier chip.
thx for the info of decoupling, what is PLL?TheDirty:
This is how you use decoupling capacitors.http://www.cvel.clemson.edu/emc/tutoria … ing01.html
Don’t forget the PLL.
Seriously, move to an easier chip.
See the documentation!
take a look at this pdf would this work?
http://www.2shared.com/document/rMkYv2l … ayout.html
Also, in the jtag manual it says that the power is drawn from the board, does this mean I connect arm7 vref pin to jtag vref pin?
Also, the vdd that are connected in this pdf run on different volts, how will I use them using one battery ?
That download is music, not a PDF!
Vref isn’t used. See the JTAG documentation on the ARM web site for the connections, or the LPC2000 group files.
the download button is at the bottom where it says Save file to your PC: click here
There are many problems with that layout.
d4n1s:
thx for the info of decoupling, what is PLL?
Have you worked extensively with some other ARM based board before you undertook designing (reinventing) your own?
From the Q&A here, it seems like “no” is the answer and that should serve as a recommendation.
Really, this is way over your head. Start with something simpler or buy a small board. For reference, all of the Olimex boards have schematics available for them. Use them to check your design. I have no idea what chip your using, but for example, the LPC2103 header board schematic:
I have LPC2138 Here is another schematic… I will have to add that I have seen a board of arm7 that a guy didn’t used any of those u mentioned… and he managed to interface a cmos camera with it that could track objects… anyways here is a schematic http://www.2shared.com/document/fXCeCAW … matic.html
Tell me if this is any better or suggest me another schematic… I have searched on ur site leon and couldn’t find any schematic for LPC2138
I thought you wanted a typical layout. The chips are similar in terms of supplies and decoupling.
I want a simple layout…well I am really confused. Anyways lets start from the begging…
What do I need to add to my board? Decoupling and a Crystal Oscillator Only?
