How to get TCK check byte of a ATR command

How to get TCK check byte of a ATR command?

Answer: 

TCK check byte of a ATR command is calculated with the XOR operation from byte T0-T7(The byte before TCK byte).


The following diagram illustrated an examples of ATR from TS 102.221:

Example of ATR and description

The following diagram illustrated program to do the XOR operation:

Program to do XOR operation