Lpc2000

Hey there Massimo,

Your reply was very helpful as I'm looking to write a bootloader 
component to update user code. You might be able to help me with 
this problem:

Let's say I have Flash Memory set up like below.....

---------------------------
User Program (space 2)    | --assume empty
---------------------------
User Program (space 1)    | --holds original code
---------------------------
Interrupt Block           |
(includes Handler + ISRs) |
---------------------------
Software Bootloader Block |
---------------------------
Reset Block               |
(Interrupt Jumps)         |
+ initializer routines    |
---------------------------

After downloading newer version code to space 2, what must be done 
to make the system execute from space 2 instead of space 1? 

thanks in advance,
Leighton



--- In lpc2000@yahoogroups.com, Micron Engineering <micronpn@t...> 
wrote:
> Ok, then if you need to write a bootloader it is a different thing.
> 1. Start studing the possibility to use LPC way to program the 
flash 
> with ISP bootloader and/or using JTAG
> 2. If the previous approach doesn't work for you, you have 
basically to 
> store in flash your bootloader (but it is compiled to work 
residing in ram)
> and then when you need to program the flash:
> - copy bootloader code in ram
> - start executing code from ram
> - use some space in ram to collect data to program on flash (a 
block 
> multiple i.e. 2KB)
> - program flash coping data from ram to flash
> - provide a communication protocol with some arbitration because 
write 
> to flash takes some time
> - provide the communication protocol with a command to reset the 
LPC
> - provide a timeout in bootloader code to automatically reset the 
LPC if 
> no data received for more then x milliseconds.
> I wrote some bootloaders for various microcontrollers to use 
different 
> interfaces to program microcontrollers or flash chips working in 
this 
> way and they perform very well. May be that you also require some 
sort 
> of ram backup and some sort of security if the programming 
procedure 
> stops before the end (i.e. power failure). Due t the big ram space 
on 
> LPC microcontrollers may be not so difficult to obtain these 
goals. 
> Remember that ARM7 is a RISC microcontroller with no different 
address 
> space for data and code, so you have only to write a relocatable 
program.
> Best regards,
> Massimo Manca, Micron Engineering
> 
> gilles_baracoda wrote:
> 
> > Actually what I would like to do is upgrade the code of the 
MCU...so
> > I have no choice but writing the internal flash!
> >
> > Thanks for the reply anyway.
> > Regards,
> >
> > Gilles
> >
> > --- In lpc2000@yahoogroups.com, Micron Engineering 
<micronpn@t...>
> > wrote:
> > > I think that if you haven't a lot of data to write it is more
> > simple and
> > > time efficient to use a simple I2C  eeprom or  an SPI eeprom
> > external
> > > connected to the LPC. Flash programming generally is used to 
write
> > > calibration data and so on during production or calibration not
> > many times.
> >
> >
> >
> > Yahoo! Groups Sponsor
> > ADVERTISEMENT
> > 
<http://us.ard.yahoo.com/SIG=1292cceqj/M=298184.5022502.6152625.30011
76/D=groups/S=1706554205:HM/EXP=1087461081/A=2164331/R=0/SIG=11eaelai
9/*http://www.netflix.com/Default?mqso=60183351> 
> >
> >
> >
> > -----------------------------------------------------------------
-------
> > Yahoo! Groups Links
> >
> >     * To visit your group on the web, go to:
> >       http://groups.yahoo.com/group/lpc2000/
> >        
> >     * To unsubscribe from this group, send an email to:
> >       lpc2000-unsubscribe@yahoogroups.com
> >       <mailto:lpc2000-unsubscribe@yahoogroups.com?
subject=Unsubscribe>
> >        
> >     * Your use of Yahoo! Groups is subject to the Yahoo! Terms of
> >       Service <http://docs.yahoo.com/info/terms/>.
> >
> >