Content originally posted in LPCWare by capiman on Sat Mar 22 00:16:35 MST 2014
All of them have a bootloader (in ROM, not replaceable). Download the User Manual (not Datasheet) for the given device,
and search for ISP. There is a chapter in each User Manual describing the way and protocol of
the built-in bootloader.
Pay attention: there are two parts described in this chapter: ISP and IAP.
They are different things.
ISP is when you program (flash, download) your program (application) from the outside the device
(like when you download a new software via FlashMagic).
ISP is started e.g. when device is started or resetted and at the same time a certain pin have a certain state.
IAP (In-Application-Programming) is doing almost the same, but the control is in your application.
Like you have written an application which shall write data (e.g. some configuration data) to certain (free) flash sectors.
But this has limits, like number of write cycles. Or you can (must) erase one complete sector, before it can be rewritten.