CCS/MSP430FR2676: Debug printing question

There are two ways to get debug log on FR family, by UART and by mailbox

UART is a typical way. Better is to use dedicated UART / CDC bridge board / chip (that is working on FR voltage) than MSP-FET  integrated UART / CDC bridge...

https://e2e.ti.com/support/microcontrollers/msp430/f/166/t/963935

Mailbox is the best way, because there is no setup and extra wires, with handshake included. Few lines of code for transfer over existing SBW / JTAG connection. Unfortunately it is not supported by any TI FET master,

At the beginning I was using 1 Mbps UART, but for last 10 years I am using  mailbox, with my SBW master for fast logging from free running device...

Thanks for the response.

If possible, I'd like to NOT use either of the two external UARTS because they are dedicated for something else in our design, I just need a simple debug output to print debug messages and if I can do that through the JTAG, that would be great!

So, few more questions:

Q1. In the second half of your response, it sounds like you are referring to a "back channel UART" right?

q2. Do you know if the "back channel UART" is available on the MSP430FR2676 part? Or, is that referring to a "Back Channel UART" on the debugger itself? I am using the CapTIvate debugger to program and debug our part, would this debugger have a Back Channel UART?

q3. When you mentioned "Unfortunately is not supported by any TI FET master" - is the MSP430FR2676 considered a FET master? I'm not sure what you mean by this.

q4. Is "MailBox" is an external program (like tera-term)?

Thanks!!!

One more thing:

Per this link:

www.ti.com/.../CAPTIVATE-PGMR

It mentions "USB HID Bridge" - would this be considered the equivalent to "Back Channel UART"?

If you need more than two hardware UART's that FR device have, one extra for debug log, than it can be implemented in software, but in this case interrupts can not be used.

Without timer... https://forum.43oh.com/topic/1284-software-async-serial-txrx-without-timer/

With timer... https://forum.43oh.com/topic/543-full-duplex-software-uart-for-launchpad/

This CAPTIVATE-PGMR board is new to me, I see dedicated USB hub chip with 2 MSP430F5528, one is FET and another is for UART / I2C communication bridge. Don't know where is (FET) Back Channel UART connected and if it is already occupied by setup, or it is free. On schematics it is marked as EZFET_RXD and EZFET_TXD.

Mailbox is device hardware add-on to SBW / JTAG interface, for data exchange between SBW / JTAG master (FET) and slave (FR2676) device without extra wires. It is integrated inside SBW / JTAG. All FRAM devices have it.

Any user bridge that can be used by (any) terminal on PC side is typically CDC, not HID. Except some vendor related products that use another interface between board and PC side with vendor supplied GUI.

Hi Dave,

Have you made any progress or are you still in need of assistance?

Dennis:

I am just returning from a holiday break, hoping to dive back into this this week.

Thanks!!

Dave...

Hi Dave,

Sounds good.  Keep me advised.

I want to also clarify that the HID bridge on the CAPTIVATE-PGMR only to supports an  I2C/UART interface between the MSP430FR2676 and the Captivate Design Center GUI.  It cannot be used as a general purpose UART bridge interface to the PC, as the backchannel UART feature of the programmer portion of the CAPTIVATE-PGMR PCB does.

It is very possible to use I2C on the MSP430 to communicate with the GUI through the HID bridge, then populate the two small DNP resistors with 0-ohm resistors and remove the TXD, RXD jumpers on J2 to route the UCA0 (P1.4, P1.5) to the programmer's backchannel interface.

Regarding the terminal in CCS, you would configure the baud rate to match the baud rate you have configured for MSP430's UART.