LPC21xx/FLASH

The FLASH in the LPC21xx devices can be programmed:

1. Via JTAG, for mass production programming and/or development (debugging can be done via the same port; see LPC21xx/JTAG)
2. Via the ISP bootloader, which is invoked by holding pin P0.14 low during a reset and then communicating via one of the RS232 ports (see LPC21xx/ISP)
3. Via the IAP interface, which can be called by your own code at run time (see LPC21xx/IAP?)

The FLASH must be erased in 8KB blocks but can be written in blocks as small as 512 bytes.