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LPC2148 is slow in Realview

Dung Han

Dear all,
I am using Realview (evaluation) and have the following program for LPC2148:

#include <LPC214x.h>
#define LED 0x01000000
main() {
        IO1DIR |= LED;  //use P1.24
        for(;;){
          IO1CLR |= LED ;
          IO1SET |= LED;
  }
}


the crystal is 12M and multiple factor is 5, no VPB setup (i also tried VPBDIV=1). It means the system should run with CPU clock=60Mhz
The problem is the LED blinks only with 1 MHz.
I tried simulation but the time shown there still indicate that the LED blinks with frequency around 30Mhz.
This happen not only with the LED but with any code i put. It seems that my system runs with 2Mhz CPU clock. Does any one have the same problem, please help me. Thanks a lot.

Parents
  • 0 in reply to ImPer Westermark

    Thank you. But I think the pin and peripheral are not the problem. The LED is just one example. Actually I tried to put more code such as:

    while(1)
{
    IO1CLR=LED;
    CodeTakes5msWith60MHZClock():
    IO1SET=LED;
    CodeTakes5msWith60MHZClock():
}


    I expect to have LED blink with the cycle of 10ms but in fact it blinks with much slower cycle, around 200ms-300ms (20 times slower). I also use UART0 and timer 0 and they work with correct timing. I dont use IAP for Flash.

Reply
  • 0 in reply to ImPer Westermark

    Thank you. But I think the pin and peripheral are not the problem. The LED is just one example. Actually I tried to put more code such as:

    while(1)
{
    IO1CLR=LED;
    CodeTakes5msWith60MHZClock():
    IO1SET=LED;
    CodeTakes5msWith60MHZClock():
}


    I expect to have LED blink with the cycle of 10ms but in fact it blinks with much slower cycle, around 200ms-300ms (20 times slower). I also use UART0 and timer 0 and they work with correct timing. I dont use IAP for Flash.

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