The STM supports timestamping of trace using values from a system global counter. The configuration port, TSMAXWIDTH, sets the maximum timestamp field width in the STM output to 48 or 64 bits:
tie TSMAXWIDTH HIGH to set a full timestamp width of 64 bits
tie TSMAXWIDTH LOW to set a full timestamp width of 48 bits.
The timestamp is either natural binary or Gray code encoded depending on the value of the TSNATURAL configuration port.