TM4C1294NCPDT: firmware downloading from production line

Hi Bob,

Thanks for your information.

I had took a look of the app note, and it looks like I can use the USB interface for firmware download to the MCU, when the chip is blank. Did you suggest to use this method on production line also?

Franky,
I'd like to jump into the discussion here.
First, I believe that USB will add unnecessary complexity to the setup - but I'm saying that with no experience. My choice is to use simple serial communication via UART0.
As for having the jtag port on the board - even if not used in production - we searched the subject, and I came across this solution: http://www.tag-connect.com/
In the end, we did not adapt this particular one, for it was not exactly for TM4C and some intermediate connections would require adapters, and further, the board layout still too a bit of excessive real state on the holed version. We might eventually draw our own thing - but the concept is quite good.
It would be nice to hear what others think/experienced.
Regards
Bruno

Dear Bruno,

If I use serial interface for the firmware downloading in the production line, I need:

1. confirm that the boot ROM from the MCU can use UART for firmware download (Please note that the MCU is blank, and do not programmed before)

2. a USB to UART hardware driver, to connect PC and the target board

If I use USB interface for downloading, then I need:

1. USB cable, which connect the PC and to the target board;

2. take the 5V from the USB as the main supply for the board, as my board will have 5V to 3.3V LDO

This is my assumption. If this is wrong, please correct me.

Thank you!

Franky,
SERIAL
1) Yes, you can download FW via UART on a blank chip. The ROM bootloader will take care of that.
2) You need USB to UART hardware OR, if you prefer a reliable production line, use an internal PCI board with RS232 ports - by the way, you will still need to convert RS232 logic to TTL levels.
BUT The advantage for UART is that you can actually get rid of the PC, and for example just use a TM4C launchpad to program your products. If your code is small enough, you don't even need external memory, the target code can be stored inside a "big" TM4C1294 flash. The program to do that would be fairly simple. Zero PC, zero hassle, anyone with a small prepared launchpad could do the downloading job.
USB
I never tried USB bootloader - or anything USB on TM4C's to be honest. Can't guide you on that.
Cheers
Bruno

Thanks for your suggestion. It really help me a lot.