Lpc2000

Landrum,

what you describe sounds reasonable though not trivial. While
receiving characters, you need to have the int vectors remapped to the
SRAM and the ISR itself needs to be in SRAM too. 

There have been discussions about replacing the bootloader with
customized versions but as far as I remember the best argument from
Philips was that handling IAP can only be compatible across many
devices when one bootloader is always used. Modifying the bootloader
has significant risks for reliability of flash programming and I
understand that Philips does not want to risk any reliability and may
be liability issues.

Having the same calling convention even if the bootloader changes is
worth a lot for reusability of the code written for the LPC2000 devices.

Sometimes I wish the source would be published but I agree that the
potential chaos with modified bootloaders is not desirable. 

Bob

--- In lpc2000@yahoogroups.com, Landrum Haddix <lhaddix@i...> wrote:
> Bob,
> Thanks, that's the answer I was hoping for. I appreciate the
> prompt and accurate assistance.
> 
> I need to run14.7456mhz * 4 with pclk 1:1 while updating
> flash. I need to not miss chars in a serial stream during
> flashing or lose cycles of a system tick so I have the interrupt
> vector table and receive ISR in ram so I can continue running
> while the IAP calls block in the foreground. I assume the IAP
> can handle periodic interrupts while it is working as long as they
> save context. Does this all sound reasonable?
> 
> Have you ever seen source for the IAP routines?
> 
> Have you ever seen source for the boot loader routines?
> 
> Have you seen a procedure for replacing the bootloader
> with a custom version. If a .hex file places code in the bootloader
> area (while it isn't  remapped) will the phillips flash utillity
> correctly write it?
> 
> My project includes a requirement to replace the default boot loader
> code with a version that boots from a different data format 
> (a proprietary RS485 based protocol) so I need to make the 
> 'factory load' while the default ohillips loader is present  replace the
> bootloader so subsequent re-flashings can be done over the 485 link.
> 
> 
> Landrum Haddix
> lhaddix@i...
> http://web.qx.net/lhaddix