The SMTxTMR register is the 24-bit counter/timer used for measurement in each
of the modes of the SMT. Setting the RST bit clears the SMTxTMR register to 0x000000. It can be
written to and read by software. It is not guarded for atomic access, therefore reads
and writes to the SMTxTMR register should be made only when GO= 0.
The counter can be prevented from resetting at the end of the timer period
by using the STP bit. When STP = 1, the
SMTxTMR will stop and remain equal to the SMTxPR register. When STP =
0, the SMTxTMR register resets to 0x000000 at the end of the
period.