• State
  • Locked Locked
  • Replies 2 replies
  • Subscribers 80 subscribers
  • Views 321 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

BSL entry timing

Dan-o
Intellectual 895 points
Other Parts Discussed in Thread: MSP430F5340

I am trying to use an FTDI usb to UART cable to program an MSP430F5340. I can drive the TEST pin with RTS, but do not have a DTR signal to drive the MSP430 ~RST pin.

My idea: have a jumper on the board that holds MSP430 ~RST low. A LED on the board will flash with the signal on the TEST pin, and the user will remove the jumper once the LED comes on for the 2nd time.

My questions:

Is there a timing requirement for entering the BSL? My solution will be pretty slow, it will take the user a second or 2 to remove the jumper on ~RST once the TEST has had 2 rising edges.

Does TEST have to go low again after entering BSL?

  • 0
    Guru 34483 points

    All USB-UART cables/chips have also DTR signal. Your solution is too slow, and not practical at all. If I remember right, from the time when I was working on my BSL, USB-UART bridge is to slow for entry sequence with new MSP430F5xx/6xx devices.

    If you have Launchpad, it can be used as BSL base for flashing other devices http://www.ti.com/lit/an/slaa535a/slaa535a.pdf

    Here is entry sequence...

  • 0
    Guru 227245 points

    Dan-o said:
    My idea: have a jumper on the board that holds MSP430 ~RST low. A LED on the board will flash with the signal on the TEST pin, and the user will remove the jumper once the LED comes on for the 2nd time.

    Not a bad idea, but it won't work. Teh user (any user) will be way too slow to remove the jumper in time. Not to mention any signal bouncing at the jumper removal.

    In theory (from teh MSp side) there is no tiem limit until the RST needs to be released. But the software that tries to access teh BSL won't likely be so patient and report a timeout or other error long before you manage to remove the jumper.

    My suggestion was to use a flip-flop that holds RST low after power-up and releases it when the PC has pulled the RST line (connected to the flip-flop, not the MSP) low and released it. Further resets are passed-through too

**Attention** This is a public forum