MSP430 MCU controls IO port operation - LED flashes

//*******************************************************************************
// D13x Demo - Change the system clock based on the previous section and observe the blinking frequency of the LED light
//
// Description: Change the blinking frequency by changing the system clock; invert P1.5 through P1 XOR; software loop delay
// ACLK= n/a, MCLK= SMCLK= default DCO ~ 800k
//
// MSP430F13x
// -----------------
// /|\| XIN|- 
// | | |
// --|RST XOUT|-
// | |
// | P1.5|-->LED
//
//
// Hardware circuit: MSP430F135 core experiment board-I type
// Hardware connection: 
//
// Debugger: MSP430FET full series JTAG emulator
// Debug software: IAR Embedded Workbench Version: 3.41A Compile
//*******************************************************************************

#include

void main(void)
{
WDTCTL = WDTPW + WDTHOLD; // Stop watchdog

P1DIR |= 0x20; // Set P1.5 as the output port

// BCSCTL1= 0x80; // Select the frequency division resistor to be 0 (the flashing frequency is slower at this time)
// BCSCTL1= 0x87; // Select the frequency division resistor to be 7 (the flashing frequency is faster at this time)

// BCSCTL2= 0xc0; // Select an external 32768 low-frequency crystal oscillator as MCLK (the flashing frequency is extremely slow at this time)
// BCSCTL2= 0x10; // Select an external 8M high-frequency crystal oscillator as MCLK (the flashing frequency is faster at this time)

for (;;) 
{
unsigned int i;
i = 50000; // Loop
do i--; while (i);
P1OUT ^= 0x20; // Invert P1.5 by XOR
}
}