EFM32WG Datasheet, PDF (524/834 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 20.6. TIMER Quadrature Encoded Inputs
Channel A
90°
Channel B
Forward rot at ion (Channel A leads Channel B)
Channel A
Channel B
90°
Backward rot at ion (Channel B leads Channel A)
In the Timer these inputs are tapped from the Compare/Capture channel 0 (Channel A) and 1 (Channel
B) inputs before edge detection. The Timer/Counter then increments or decrements the counter, based
on the phase relation between the two inputs. The Quadrature Decoder Mode supports two channels,
but if a third channel (Z-terminal) is available, this can be connected to an external interrupt and trigger
a counter reset from the interrupt service routine. By connecting a periodic signal from another timer as
input capture on Compare/Capture Channel 2, it is also possible to calculate speed and acceleration.
Figure 20.7. TIMER Quadrature Decoder Configuration
Com pa re /Ca pt ure cha nne l 0
(Cont rolled by TIMERn_CC0_CTRL)
TIMn _CC0
PRS channels
PRSSEL
INSEL
Filt er
FILT
Com pa re /Ca pt ure cha nne l 1
(Cont rolled by TIMERn_CC1_CTRL)
TIMn _CC1
PRS channels
PRSSEL
INSEL
Filt er
FILT
ICEDGE
Input
Capt ure 0
Count e r
(Cont rolled by TIMERn_CTRL)
QDM
MODE
Ch A
Ch B
Qua dra t ure
D e cod e r
Inc Count e r
Dec
ICEDGE
Input
Capt ure 1
The Quadrature Decoder can be set in either X2 or X4 mode, which is configured in the QDM bit in
TIMERn_CTRL. See Figure 20.7 (p. 524)
20.3.1.6.1 X2 Decoding Mode
In X2 Decoding mode, the counter increments or decrements on every edge of Channel A, see
Table 20.1 (p. 525) and Figure 20.8 (p. 525) .
2013-05-08 - Wonder Gecko Family - d0233_Rev0.50
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