Scan-programmable thresholds are set using multiplexers to
select the desired TDC output bit. To avoid mismatch
between rising and falling delays in the TRC, the DVM is only
enabled on alternate core clock cycles, corresponding to a 1-
cycle accuracy and a 2-cycle readout. The DVM and core
share the same VCC, thus capturing the effects of VCC and
temperature variations on data and clock distribution delays
[5]. The TDC output can be translated to frequency, voltage,
or temperature. DVM frequency (FDVM) is determined by
placing the core into a quiet state and observing the TDC
output at different FCLK values. Similarly, the TDC output is
mapped to VCC or temperature by observing the TDC output at
different VCC or temperature values.