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LPC2106 JTAG Programming Confusion!!

Started by amerdsp August 26, 2007
Greetings,
  I am reading mixed information about the ability to program the 2106
using a parallel port wiggler.  Some say that it is only possible to
program the device via RS232 but others say that it is possible to do
the JTAG programming.

What am I missing? What do I need to have to be able to use JTAG for
programming the chip if possible?

Thank you,

-- A

On Aug 26, 8:04 am, amerdsp <amer...@hotmail.com> wrote:
> Greetings, > I am reading mixed information about the ability to program the 2106 > using a parallel port wiggler. Some say that it is only possible to > program the device via RS232 but others say that it is possible to do > the JTAG programming. > > What am I missing? What do I need to have to be able to use JTAG for > programming the chip if possible? > > Thank you, > > -- A
Hi, You can program you LPC through JTAG. NXP embedds a bootloader in its LPC devices.This bootloader allows you to program the device via RS232, but it also exports its routines for onchip use (and unfortunately, this is the only way to write flash from onchip OS, as NXP doesn't document the interface for the internal flash controller). So, in order to program your device using JTAG, you have to write a piece of code that you will push into the chip RAM (using JTAG). You piece of code will call the NXP bootloader flash routine, and will be able to communicate with you PC-hosted programmer over JTAG (for ex, push data in RAM buffer, push arguments in registers, push program routine address in PC, run). This is not the funny part and you are walking in the dark when you do something like this. Therefore, for 70=80 I would rather direct you to http://www.isystem.com. They sell a nice starter dev kit including a rather complete IDE, a USB JTAG wriggler and a LPC2138 header board. I have just bought one and I definitely don't regret my money. I just checked, LPC2106 is supported. Even if you don't want to buy their kit, you can have a look at their free demo, they might include source for the chip side downloader (though it will be design for their own PC side downloader). By the way, if anyone has information about LPCs flash controller registers, I am definitely interested. I am currently trying to reverse their bootloader to extract this information, but this is about 12k binary dump to inspect... I don't want to rely on "third party" software for my low level code Cheers, St=E9phane

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