LPC 2138 code is not executing

Hello sir,
I am using ISP mode (UART 0 - RS232)for programming & External oscillator(12 MHZ ).
I used flash magic for loading HEX file & it's successfully loaded. but after loading HEX file program is not executed .I check reset circuit it's properly working when reset switch is press reset pin make low(0).I include startup file in my LED Blinking project.
I don't have any JTAG Interface. But my code working properly in Proteus .I don't know what actual issue is there any RESET PROBLEM or Crystal PROBLEM .& one thing is that sometimes when i touch the crystal XTAL 1(pin-62) pin using voltmeter probe(voltmeter in continuity or dc volt mode) LED start blinking or some time LED continuously ON .

Hear my code- LED BLINKING
#include <lpc213x.h>

void delay(unsigned long val);
int main(void)
{ IO1DIR = 0xFFFFFFFF; // Configure all pins on Port 0 as Output

while(1) { IO1SET = 0xFFFFFFFF; // Turn on LEDs delay(5000000);

IO1CLR = 0xFFFFFFFF; // Turn them off delay(5000000); } // return 0; // normally this wont execute
}

void delay(unsigned long val)
{ while(val>0) { val--; }
}

Thank you.

Hello sir,
I am using ISP mode (UART 0 - RS232)for programming & External oscillator(12 MHZ ).
I used flash magic for loading HEX file & it's successfully loaded. but after loading HEX file program is not executed .I check reset circuit it's properly working when reset switch is press reset pin make low(0).I include startup file in my LED Blinking project.
I don't have any JTAG Interface. But my code working properly in Proteus .I don't know what actual issue is there any RESET PROBLEM or Crystal PROBLEM .& one thing is that sometimes when i touch the crystal XTAL 1(pin-62) pin using voltmeter probe(voltmeter in continuity or dc volt mode) LED start blinking or some time LED continuously ON .

Hear my code- LED BLINKING
#include <lpc213x.h>

void delay(unsigned long val);
int main(void)
{ IO1DIR = 0xFFFFFFFF; // Configure all pins on Port 0 as Output

while(1) { IO1SET = 0xFFFFFFFF; // Turn on LEDs delay(5000000);

IO1CLR = 0xFFFFFFFF; // Turn them off delay(5000000); } // return 0; // normally this wont execute
}

void delay(unsigned long val)
{ while(val>0) { val--; }
}

Thank you.

The capacitive load from the multimeter might make the crystal oscillator fail to operate. But it might also get an oscillator that doesn't run correctly to start generate the expected 12MHz.

Best is to have access to an RF analyzer that can listen to the oscillator without electrical connection. Second best is probably a scope probe in 10:1 mode, after you have calibrated the capacitance using the test output of the oscilloscope.

But notice that it makes a lot of difference which of the two crystal pins you look at. One oscillator on the processor is input and one is output. It's way better to probe the output pin that drives the crystal.

I think NXP names the input pin XTAL1 and the output pin XTAL2 for your processor. That's at least the naming they have for a number of newer chips.

But did you test to modify the code to run the RC oscillator instead? Just to figure out if your troubles are related to the crystal frequency and stability?