Lpc2000

For reference the posting we did on Dec 22
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1) Am I right in assuming LPC2000 CRP is a software fence implemented
in the supplied boot loader code?

Partially. It is a combination of Hardware and Software supplied in
the bootloader code. Application running in micro has full access to
the entire memory space.

2) I am going to replace the Philips bootloader. I have figured out
how to do it.

Replacing the Philips bootloader is not recommended. It hides the
underlying hardware and allows Philips to use new flash technologies
without impacting the end user. Philips Bootloader may reside in ROM
or write/erase protected flash making replacement impossible. In
LPC2101/2/3 the bootloader resides in on-chip ROM.

3) How is Bootloader programmed for the first time?

Via JTAG on a tester. JTAG is accessible in virgin devices. Once
bootloader is programmed and CRP is enabled the tester can't access
the JTAG.

4) CRP in devices with internal flash and external bus.

The bootloader prevents external boot if CRP is enabled. User
Application residing in on-chip flash which needs to be protected
should not execute code from external memory.

5) Can bootloader write/erase itself?

No.

6) Can bootloader get corrupted?

Very unlikely if IAP/ISP calls are used for flash programming.
Very likely if Flash programming interface registers are directly
accessed for flash programming.

7) Can Philips comment if Quick-Pulse parallel programming can void 
CRP?

First of all there is no Quick-Pulse parallel programming option for
ARM based micros. We are sorry for not making clear what is meant by
"Parallel Programming" for ARM based micros. Parallel programming for
ARM based micros just means that the device can be mass programmed in
a commercial programmer. Parallel programmers still use JTAG and/or
ISP and go through the bootloader IAP routines to program the on-chip
flash. It does not matter how a part is programmed. If CRP is enabled
it will remain enabled once the part is programmed. If CRP is enabled
a parallel programmer can't access the flash unless it erases the
whole flash. Same applies to the ISP utility and JTAG based 
debuggers.

8) Is CRP option available for 2104/05/06?

Not yet.

9) Devices with external memory bus can be forced to boot from
external memory?

ONLY if CRP is NOT enabled or NO internal flash present. Also see 
(4).

10) Can I tell client Philips has confirmed CRP is not voided by PP?

Yes. Also see (7).

11) How do I reprogram a CRP enabled part?

Erase all user sectors in one go via ISP. You can reprogram it after 
a
power cycle.
Please note that the protected code vanished and was not visible to a
"spy" or "praying eyes".

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12) Can JTAG be or remain enabled through clocking the CPU slowly 
and JTAG fast during the initial time window after reset where JTAG 
is enabled?

No, the clock for JTAG and the CPU are syncronized on these devices. 
There are not enough JTAG clocks to control the CPU before the JTAG 
gets disabled by the bootloader software. 

13) Can the bootloader update be performed when CRP is enabled?

No, the bootloader update uses commands like copy RAM to Flash which 
is disabled when CRP is enabled. The message will be that there is 
no communication possible. 


Comment to Robert Adsets posting:
It is correct that support efforts would be significantly higher 
with published source code of the bootloader and let me add without 
adding any benefits to you, our customers.