This comparison counts edges in moving
time window. Moving time window is the same time window but with overlap start
within existing window. This allows better granularity to check that edge counts are
uniform in the window and if those are changing the transition is smooth.
For example:
- If the moving timing window
(MVWTIME) is configured to 2000 time-base counts and number of readings
(MVWCNT) is configured to be 3 (0x3).
- Then after trigger signal
edges are counted for every 2000 time-base count. Readings of multiple (2 or
3), in this case (MVW_CNT) 3, moving windows are accumulated to make one
fixed window.
- Thus the size of the fixed
window is 6000. After first fixed window measurement is over, the
measurement is compared against SIGxCMPA/B and the corresponding margin to
verify the measurement is within the minimum-maximum range.
- Further upon next moving
window reading accumulation, it is added to fixed window measurement and the
earliest reading is retired (subtracted) from the signal edge count of the
fixed window. Thus the reading to be compared is always maintained for one
fixed window. For example, Windows intervals successively progress for time
base counts of 0-6000, 2000-8000, 4000-10000, 6000-12000, so on.
- The given size of the moving
window is configured in the SIGxEDGEMVWCFG[MVWTIME] and the number of moving
windows SIGxEDGEMVWCFG[MVWCNT] is to be accumulated.
- Moving window count MVWCNT is
limited to 1, 2, 3, or 4 of which a count of 1 means that there is no moving
window. Either bisect or trisect the fixed window with as many readings (3
readings for bisect and 4 for trisect) to manipulate.
- As depicted multiple accumulator
snapshots can be taken for the measurement count at the interval of MVWTIME and
readings are computed to find the number of edges within MVWTIME ˟ MVWCNT
period. Check of readings after every snapshot gives granular movement of
window.