MSP430F5510 USB not responding

It is default USB BSL, and all MSP430F5510 devices have same BSL version? You are entering to USB BSL mode by BSL button? What about PUR pin, and voltage (3.3V) on it, when it is pulled high?

ZRNO,

Thanks for the help. 

"It is default USB BSL, and all MSP430F5510 devices have same BSL version?"  -Yes we checked and they are all the same version.

"You are entering to USB BSL mode by BSL button?" -We do not use the BSL button normally. For sure we do not use the BSL button on the 6 units that work. However, for de-bug we did use this button.

"What about PUR pin, and voltage (3.3V) on it, when it is pulled high?" -We have not checked this. So thanks for the tip. I will measure this pin voltage and let you know the results.

Thanks again for your time.

V/r,

Chuck

Zrno,

Some more information about my problem with the USB follows:

The hardware was copied from the MSP-TS430RGC64USB breakout board in terms of schematic, and we do use a 4 MHz crystal for XT2.

When the MSP430F5510 reaches the following lines of code in the debugger:

if(fInvokeBSL)

{

__disable_interrupt(); // Ensure no application interrupts fire during BSL

((void (*)())0x1000)(); // This sends execution to the BSL. When execution

// returns to the user app, it will be via the reset

// vector, meaning execution will re-start.

}

I can see that it enters the second line and enters the factory-programmed BSL at address 0x1000.  On the devices that work, we get communication on one of the data lines as shown in image 1.

On the devices that do not have a working USB, after I plug in the USB cable, there is no communication on the line at all - it stays dead at 0.  However if I have the "failsafe" button held down that forces the device into USB update mode at power on, I get "device not recognized" and see the data waveform in image 2.

Between the working and nonworking boards, the hardware appears identical (verified by multimeter), the same firmware is programmed onto each MSP430, and we were able to retrieve the BSL .txt file using the MSP430Flasher command line utility and verify that both sets of boards have identical software loaded onto them as well, in addition to reprogramming the BSL onto the boards, none of which helps.  The XT2 clock signals also look identical between boards as well.

We checked the PUR pin and have the scope plots for you to see. The first image is that of a working USB unit.

The second image is that of the non-working USB micro-controller.

You can see the voltage sags when there is data output. Do we need to add an external pull-up?

Thanks again,

Chuck