RM0046 eTimer
Doc ID 16912 Rev 5 731/936
TRIGGERED-COUNT mode
When the CNTMODE field is set to 110, the counter will begin counting the primary clock
source after a positive transition (negative if SIPS = 1) of the secondary input occurs. The
counting will continue until a compare event occurs or another positive input transition is
detected. Subsequent secondary positive input transitions will continue to restart and stop
the counting until a compare event occurs.
Figure 414. Triggered Count mode (length = 1)
ONE-SHOT mode
When the CNTMODE field is set to 110 and the counter is set to reinitialize at a compare
event (LENGTH = 1), and the OFLAG OUTMODE is set to 0101 (cleared on init, set on
compare), the counter works in ONE-SHOT mode. If an external events causes the counter
to count, when terminal count is reached, the output is asserted. This delayed output can be
used to provide timing delays.
Figure 415. One-Shot mode (length = 1)
CASCADE-COUNT mode
When the CNTMODE field is set to 111, the counter’s input is connected to the output of
another selected counter. The counter will count up and down as compare events occur in
the selected source counter. This cascaded or “daisy-chained” mode enables multiple
counters to be cascaded to yield longer counter lengths. When operating in cascade mode,
a special high speed signal path is used between modules rather than the OFLAG output
signal. If the selected source counter is counting up and it experiences a compare event, the
counter will be incremented. If the selected source counter is counting down and it
experiences a compare event, the counter will be decremented.
Either one or two counters may be cascaded to create a 32-bit wide synchronous counter.
12 13 14 15 16
COMP1 = 18
17 18
Primary
Secondary
CNTR
OFLAG
0 1234
LOAD = 0, COMP1 = 4
0123
Primary
Secondary
CNTR
OFLAG
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