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EFM32WG Datasheet, PDF (582/834 Pages) List of Unclassifed Manufacturers – The EFM32WG Wonder Gecko is the ideal choice for demanding 8-, 16-, and 32-bit energy sensitive applications.
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Figure 23.2. LETIMER State Machine for Free-running Mode
Wait for positive clock edge
(RUNNING or START)
and ! STOP
NO
YES
If (STOP)
RUNNING = 0
Else if (START)
RUNNING = 1
End if
START = 0
STOP = 0
CNT = = 0
NO
YES
CNT = CNT - 1
CNT = TOP*
TOP*
If (COMP0TOP)
TOP* = COMP0
Else
TOP* = 0xFFFF
Note that the CLEAR command bit in LETIMERn_CMD always has priority over other changes to
LETIMERn_CNT. When the clear command is used, LETIMERn_CNT is set to 0 and an underflow
event will not be generated when LETIMERn_CNT wraps around to the top value or 0xFFFF. Since
no underflow event is generated, no output action is performed. LETIMERn_REP0, LETIMERn_REP1,
LETIMERn_COMP0 and LETIMERn_COMP1 are also left untouched.
23.3.3.2.2 One-shot Mode
The one-shot repeat mode is the most basic repeat mode. In this mode, the repeat register
LETIMERn_REP0 is decremented every time the timer underflows, and the timer stops when
LETIMERn_REP0 goes from 1 to 0. In this mode, the timer counts down LETIMERn_REP0 times, i.e.
the timer underflows LETIMERn_REP0 times.
Note
Note that write operations to LETIMERn_REP0 have priority over the decrementation
operation. So if LETIMERn_REP0 is assigned a new value in the same cycle it was
supposed to be decremented, it is assigned the new value instead of being decremented.
LETIMERn_REP0 can be written while the timer is running to allow the timer to run for longer periods
at a time without stopping. Figure 23.3 (p. 583) .
2013-05-08 - Wonder Gecko Family - d0233_Rev0.50
582
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