Serial comm problem in Nano monitor v1.02

[CP2102]

We're using a script to configure the IP addres etc. of our nano boards using the
serial monitor interface which runs at the default 115.2kbps. After sending a shift-A at power on
we send the 'setup' command at the 'nb>' prompt.

When sending 'setup' to a board with the new 1.02 monitor, it'll print back 'setu' or 'setp'
and then an "unrecognized command" message.

If you paste the string
"0123456789012345678901234567890123456789" it'll print back
"01245678012356790134568902345789". A board with the old V1.00 monitor works fine...

So it seem like there's a problem with the RX handling in the v1.02 monitor.

old monitor:
Netburner MCF5441x Alternate Image Monitor V1.00 May 23 2012 13:27:35

new monitor:
NetBurner MCF5441x Alternate Image Monitor v1.02 Jul 31 2019 09:42:53

[TomNB]

Hello CP2102,

I have been unable to identify any other reports of this type of behavior. Here is a change list for the monitor:

1.02 04/11/2016 Modifications to serial menu for clarifications of options
1.01 10/06/2014 Added support for NATIVEBOOT and BOOT commands
1.00 03/01/2012 Initial release

Maybe the changes to the serial menu text could have an impact?

[TomNB]

I have also run the following tests:
1. Send a script file of repeating numbers and verify all are echoed back correctly
2. Verify a serial download of a 1MB file updates the application correctly. So it seems that the receive is working in the tests I have done here.

Are you running the nano in a development board? If not, that would bee a good test and data point

In the script tests I created a text file with "0123456789012345678901234567890123456789". I then ran MTTTY and used the Send Text File option to send the file to the device.

[CP2102]

Thanks for checking this out. We see this issue using our own controller board
and the Nano carrier board (rev1.3). We've also tried using MTTTY and putty and the problem
follows the Nano board with the v1.02 boot monitor. Other than the serial issue, the
Nano board is working fine which is why we suspect there's a problem in the new boot monitor.

[TomNB]

Hello,

Thank you for testing in the nano carrier board. I tested additional 1.02 boards, and they are functioning fine for me, so I'm not quite sure what to try next in this case. Just as a data point, does it make any difference if you reduce the baud rate?

[CP2102]

Hi, yes it works fine at 57600.

[TomNB]

Hello, I was finally able to reproduce the behavior you describe. I have asked engineering to look into it. There is a lot of software involved, so I do not have a time frame on the effort. The boot monitor is a low level interface that uses polling rather than interrupts. and is meant to be a terminal interface for a human to type commands. It is not the same type of interface as an application, which is interrupt driven with buffering. Other than that, at this point we do not yet know how the changes made would affect the serial performance.

[TomNB]

Hello,

We were able to determine the issue was caused by a change made to the alternate boot monitor. That has been corrected, and the revision moved to 1.03. We still have regression testing to do before it can be released to production. Are you able to program the boards you have using a lower baud rate for the time being?

[CP2102]

That's great! I guess we'll have to update the serial port driver in our software to add some time between each character we send
since we might encounter more v1.02 boards for a while...anyway, thanks for the fix!