Thanks for your answer
Yes, in data sheet Chapter 15 Serial Peripheral Interface (S08SPIV3) I can learn to use the serial interface. I work in assembler.
It would be good to have a small code example to shorten the work.
Now the computer side. Here I would like to process the transmitted and received data in an Excel file. In the old days with Windows XP, this was possible with an SIO, written with software and reception in the PC and further processing with Excel. I suspect the is possible via a serial port with Windows 11.The second solution is a replacement solution, but very, very simple: With my measurement program I output a small amount of data in binary form on an 8-bit port. Now I have a dream that a display shows this 8-bit value in decimal. A nice and, I think, obvious task. My thought is that someone must have done that before.
And another replacement (makeshift) solution: I simply read the data stored in the flash in CodeWarrior's debug mode.
If the computing effort is low, this should also be possible without the comfort of the PC. I'm excited to see what happens next and thank you for your interest.
Best regards
Gerd