Content originally posted in LPCWare by NXP_Europe on Wed Jul 27 08:35:25 MST 2011
Hello shaileshbc,
See the User Manual ... be sure that the P2.10 has a pullup resistor.
Quote:
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[LEFT]The flash boot loader code is executed every time the part is powered on or reset. The
loader can execute the ISP command handler or the user application code. A LOW level
after reset at pin P2.10 is considered an external hardware request to start the ISP
command handler. Assuming that power supply pins are on their nominal levels when the
rising edge on RESET pin is generated, it may take up to 3 ms before P2.10 is sampled
and the decision on whether to continue with user code or ISP handler is made. If P2.10 is
sampled low and the watchdog overflow flag is set, the external hardware request to start
the ISP command handler is ignored. If there is no request for the ISP command handler
execution (P2.10 is sampled HIGH after reset), a search is made for a valid user program.
If a valid user program is found then the execution control is transferred to it. If a valid user
program is not found, the auto-baud routine is invoked.
Pin P2.10 is used as a hardware request signal for ISP and therefore requires special
attention. Since P2.10 is in high impedance mode after reset, it is important that the user
provides external hardware (a pull-up resistor or other device) to put the pin in a defined[/LEFT]
state. Otherwise unintended entry into ISP mode may occur.
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