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RAM loading via JTAG

Started by Piotr Zbysinski August 17, 2005
I plan to build Flash programmer (via JTAG) for LPC2K. Is there
anybody who knows JTAG command codes used for SRAM loading?
Rgs
Piotr


An Engineer's Guide to the LPC2100 Series

When you switch the ARM7 into debug mode, all instructions and data are
read from the jtag interface. You can just upload a ldm instruction for
example with the data following the instruction and then use a stm
instruction to store it in sram. Then you setup the registers to call
the IAP routine and set a breakpoint to the same address the LR is
pointing to. The ARM site has excelent documentation on this, so I
suggest you browse www.arm.com and lookup the information you need.

A suggestion: use a FT2232 (see
http://www.ftdichip.com/FTProducts.htm#FT2232C) for the low level JTAG
stuff, they have a JTAG DLL for windows and good documentation the write
this yourself for other platforms. All you need is this single FT2232
and some passive components to make this work.

Richard Duits
Piotr Zbysinski wrote:

> I plan to build Flash programmer (via JTAG) for LPC2K. Is there
> anybody who knows JTAG command codes used for SRAM loading?
> Rgs
> Piotr >
>
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----- Original Message -----
From: Richard Duits
To: lpc2000@lpc2...
Sent: Thursday, August 18, 2005 1:15 AM
Subject: Re: [lpc2000] RAM loading via JTAG When you switch the ARM7 into debug mode, all instructions and data are
read from the jtag interface. You can just upload a ldm instruction for
example with the data following the instruction and then use a stm
instruction to store it in sram.

** Do you mean: should I send via JTAG binary code of LDM/STM instructions?

Then you setup the registers to call
the IAP routine and set a breakpoint to the same address the LR is
pointing to. The ARM site has excelent documentation on this, so I
suggest you browse www.arm.com and lookup the information you need.
** OK, I'll try. A suggestion: use a FT2232 (see
http://www.ftdichip.com/FTProducts.htm#FT2232C) for the low level JTAG
stuff, they have a JTAG DLL for windows and good documentation the write
this yourself for other platforms. All you need is this single FT2232
and some passive components to make this work.

** JTAG is not a problem for me (I used FT2232 in universal PLD programmer/configurator IEEE1532 compatible). My idea is to prepare Windows software for simple Macraigor interface for fast programming LPC uCs.
Thanks for answer.
Piotr