Having stepped further in my IAP firmware update project I now want to flash sectors on a LPC1343. I decided to use the flash source code delivered with the KEIL MDK V4.23 (C:\Keil\ARM\Flash\LPC_IAP\FlashPrg.c). I'm wondering about a function 'Init()' which switches the processors clock to the internal oscillator. As my bootloader app has already executed its startup code, my processsor is running from an external oscillator. So, why to switch to the internal osc before flashing? Best regards, Juergen.