Lpc2000

Piotr, this may explain some confusion: (this is a direct quote from the 
J-link documentation from www.segger.com)

Quote:

6.4.1 How does flash programming via J-Link work ?
This requires extra code. This extra code typically downloads a program into 
the RAM
of the target system, which is able to erase and program the flash. This 
program is
called Ram code and "knows" how to program the flash; it contains an 
implementation
of the flash programming algorithm for the particular flash. Different flash 
chips
have different programming algorithms; the programming algorithm also 
depends on
other things such as endianess of the target system and organization of the 
flash
memory (e.g. 1*8 bits, 1 * 16 bits, 2*16 bits or 32 bits) The Ram code 
requires data
to be programmed into the flash memory. There are 2 ways of supplying this 
data:
Data download to RAM or data download via DCC.
6.4.2 Data download to RAM
The data (or part of it) is downloaded to an other part of the RAM of the 
target system.
The Instruction pointer (R15) of the CPU is then set to the start address of 
the
Ram code, the CPU is started, executing the RAM code. The RAM code, which 
contains
the programming algorithm for the flash chip, copies the data into the flash
chip. The CPU is stopped after this. This process may have to be repeated 
until the
entire data is programmed into the flash.
6.4.3 Data download via DCC
In this case, the RAM code is started as described above before downloading 
any
data. The RAM code then communicates with the PC (via DCC, JTAG and J-Link),
transferring data to the target. The RAM code then programs the data into 
flash and
waits for new data from the host. The WriteMemory functions of J-Link are 
used to
transfer the RAM code only, but not to transfer the data. The CPU is started 
and
stopped only once. Using DCC for communication is typically faster than 
using Write-
Memory for RAM download since the overhead is lower.
6.4.4 Available options for flash programming
There are different solutions available to program internal or external 
flashes connected
to ARM cores using J-Link. The different solutions have different fields of
application, but of course also some overlap.

End Quote.


>From: "Ake Hedman, eurosource" <akhe@...>
>Reply-To: lpc2000@yahoogroups.com
>To: lpc2000@yahoogroups.com
>Subject: Re: [lpc2000] JTAG commands are secret?
>Date: Fri, 04 Nov 2005 09:11:53 +0100
>
>  > Is there anybody who know why uCs producers are so secretive?
>Yes this is very sad as well as strange behavior and typical for
>European management. They are all in the thinking that they have to get
>payed for everything that are developed in house. They don't have the
>vision to see that they get a much bigger return by putting the
>information out in the open and let others improve it. The LPC family is
>the best I have seen for many years (I'm actually mainly a PIC user) but
>knowing that this type of old thinking still exists in Philips makes me
>hold back from using them on all major designs. I talked to a rather big
>Swedish company last week and they liked the LPC more then the
>competition but selected the AVR ARM instead because of the same
>reasons. And in that case we talk about a lot of pieces.
>
>I really hope that a company like Philips that so often show technical
>excelens could mature and show marketing excelens to...
>
>/Ake
>
>--
>  ---
>Ake Hedman (YAP - Yet Another Programmer)
>eurosource, Brattbergav�gen 17, 820 50 LOS, Sweden
>Phone: (46) 657 413430 Cellular: (46) 73 84 84 102
>Company home: http://www.eurosource.se
>Kryddor/Te/Kaffe: http://www.brattberg.com
>Personal homepage: http://www.eurosource.se/akhe
>Automated home: http://www.vscp.org
>
>
>