MSP430FR2355: GPIO state during UART BSL programming

Robert

Prodigy 70 points

Part Number: MSP430FR2355

Tool/software:

Hello,

What is the state of the pins(P1.0 for example) during a UART BSL programming sequence?

Input or output?

Pulldown or pullup enabled?

I'm guessing its a input with no pullup and no pull down resistor?

Thanks!

over 1 year ago

0 JD Crutchfield over 1 year ago

TI__Mastermind 30560 points

Hey Robert,

my understanding is that the BSL doesn't change the pin settings besides the two BSL related pins. MSPFRboot is basically the source code for the BSL and can be found here: https://www.ti.com/lit/an/slaa721e/slaa721e.pdf?ts=1741232439453&ref_url=https%253A%252F%252Fwww.ti.com%252Ftool%252FMSPBSL

So, if you are invoking the BSL at powerup, then the other GPIO will be in their default configuration. If the BSL is invoked by software and the pins have already been configured, then I believe they will remain configured as they were.

Does that address your question?

Thanks,

0 Robert over 1 year ago in reply to JD Crutchfield

Prodigy 70 points

Hey JD,

I might not have been clear. My MSP code is setting a pin HIGH. When I attach a device like the MSP430-BSL to reprogram the board, I'm trying to figure out the state of all the various pins. I can see on a oscope that it's going low throughout the whole programming process and then goes back high when the programming is done, but unsure if its an output, input, and whether or not its being pulled down by an internal resistor.

+1 JD Crutchfield over 1 year ago in reply to Robert

TI__Mastermind 30560 points

Hey Robert,

What are you using to invoke the BSL? It sound like it's an external BSL hardware invoke (section 3.3.2 of the MSP430 FRAM BSL User's Guide)

This means the MSP430 is going to be reset, and then boot into the BSL RESET vector instead of your application reset vector. This mean GPIO are going to be in their default reset state and according the the TRM, that is configured as an input with no pull-up or pull-down resistors.

After the BSL complete, it should run your application code which I assume is setting this pin back high.

Hope this answers you question.

Thanks,

0 Robert over 1 year ago in reply to JD Crutchfield

Prodigy 70 points

JD,

You are correct, I'm using external hardware to invoke the BSL. Specifically https://software-dl.ti.com/msp430/msp430_public_sw/mcu/msp430/MSPBSL_Scripter/latest/index_FDS.html with the https://www.olimex.com/Products/MSP430/BSL/MSP430-BSL/

I assumed it would be an input without pull down or pull up, as Table 4-1 says the following. But wanted to make sure the state of the device when it is in the middle of being (re)flashed via UART BSL wasn't different than a normal reset state.

Thanks for helping me with this question!

Robert

**Attention** This is a public forum

MSP low-power microcontrollers

MSP low-power microcontroller forum

MSP430FR2355: GPIO state during UART BSL programming