Triggering MSP430F5510 USB BSL from Software

Hi there,

I researched the issue quite a bit and mainly followed this guide:

http://www.ti.com/lit/an/slaa452b/slaa452b.pdf

Basically I want to trigger the USB BSL from the main program when a user button is pressed, so I can flash a new firmware using the "MSP430 USB Firmware Upgrade Example" (Isn't there actually another way of flashing a new firmware using usb??). I figured that you need to call 0x1000, however I'm experiencing some strange behaviour.

#include <msp430.h>

extern void invkBsl(void);

void invokeBSL(void)
{
    // SYSBSLC &= ~(SYSBSLPE);
    PJOUT &= ~BIT0;  // disable LED1 to show that function has been called

    //disable interrupts
    __disable_interrupt();

    // enter BSL
    //((void (*)())0x1000)();		// Invoke BSL
    invkBsl();  // calla #0x1000

}

int main(void)
{
  WDTCTL = WDTPW+WDTHOLD;                   // Stop WDT
  PJDIR |= 0xF;                            // PJ.0 set as output
  P6DIR = ~BIT0;							// Set P6.0 Switch as Input
  P6REN = 0x00; // Disable Pullup, as it is implemented in hardware.

  PJOUT |= BIT0; // Turn on Status LED 1
  PJOUT |= BIT1; // Turn on Status LED 2

  while(1)                                  // continuous loop
  {
	  if(P6IN & BIT0 == 0)
		  invokeBSL(); // Invoke BSL when button is pressed

	  PJOUT = (P6IN << 1) | (PJOUT & BIT0);  // Set LED2 to current Switch status
  }
}

right, now as you can see, what I expect to happen is that i press the button, Status LED1 and LED2 turns off (LED1 permanently, LED2 until button is released) and my pc should find the MSP430 as a usb device, ready to be flashed using the software tool.

Now what happens is this: LED1 is still on, LED2 turns off as long the button is beeing pressed. My explanation: The BSL is called and instantly returnes control to the main program, reactivating LED1 instantly.

So why doesn't the BSL do what happens when I pull up the PUR pin while connecting the board via usb??

Regards,

Max