Lpc2000

Thanks Jaya for your clear response. This is what I thought. I will
search for other topics since everybody advised me...

--- In lpc2000@yahoogroups.com, "jayasooriah" <jayasooriah@...> wrote:
>
> Hello,
> 
> --- In lpc2000@yahoogroups.com, "croquettegnu" <croquettegnu@> wrote:
> >
> > Hi all,
> > 
> > I would like to know what are the limitations of the CRP protection
> > because this kind of protection is controlled by the onchip bootloader
> > so by software and I think that it is perhaps less efficient than a
> > hardware code read protection feature ...
> 
> Not only less efficient but also not as safe.
> 
> > In fact, what are the solutions to access the flash code content even
> > if CRP is enabled ?
> 
> I understand there are.
> 
> No one has posted one in this forum.
> 
> Posting such a solution would IMHO be breaking relevant laws in many
> countries relating to disclosure of security circumventing measures.
> 
> > I have seen that ATMEL proposes a flash security bit which disables
> > the JTAG and prevents from flash access. This protection can not be
> > suppressed except by erasing the flash which is more secure to my mind
> > .. Am I worng ?
> 
> I do not know which variant you are referring to, but in general you
> have to look for evidence that indicates that security is supported at
> the hardware level.
> 
> A software afterthought (as I characterises the LPC CRP feature) in
> general only stops novices and gives a false sense of security IMO.
> 
> Example of hardware support in Mega32: "The Chip Erase will erase the
> Flash and EEPROM memories plus Lock bits. The Lock bits are not reset
> until the program memory has been completely erased."]
> 
> > Thanks in advance
> 
> You need to be aware that boot loader of LPC family mitigates (i.e.
> tries to reduce the impact of) but not remove the window of
> opportunity that exists between chip reset and when the boot loader
> actually disables JTAG port.
> 
> You can read the original threads (complete with insults, emotions and
> all).  I thought this summary would be useful.
> 
> Jaya
>