Silicon Laboratories EFR32xG14 Wireless Gecko Reference Manual page 662

20.3.2.5 Compare
Each Compare/Capture channel contains a comparator which outputs a compare match if the contents of TIMERn_CCx_CCV matches
the counter value, see Figure 20.14 TIMER/WTIMER Block Diagram Showing Comparison Functionality on page
mode, each compare channel can be configured to either set, clear or toggle the output on an event (compare match, overflow or un-
derflow). The output from each channel is represented as an alternative function on the port it is connected to, which needs to be ena-
bled for the CC outputs to propagate to the pins.
CNTCLK
Note: For simplicity, all
TIMERn_CCx registers are
grouped together in the figure,
but they all have individual
Compare Register and logic
Figure 20.14. TIMER/WTIMER Block Diagram Showing Comparison Functionality
The compare output is delayed by one cycle to allow for full 0% to 100% PWM generation. If occurring in the same cycle, match action
will have priority over overflow or underflow action.
The input selected (through PRSSEL, INSEL and FILTSEL in TIMERn_CCx_CTRL) for the CC channel will also be sampled on com-
pare match and the result is found in the CCPOL bits in TIMERn_STATUS. It is also possible to configure the CCPOL to always track
the inputs by setting ATI in TIMERn_CTRL.
The COIST bit in TIMERn_CCx_CTRL is the initial state of the compare/PWM output. The COIST bit can also be used as an initial
value to the compare outputs on a reload-start when RSSCOIST is set in TIMERn_CTRL. Also the resulting output can be inverted by
setting OUTINV in TIMERn_CCx_CTRL. It is recommended to turn off the CC channel before configuring the output state to avoid any
pulses on the output. The CC channel can be turned off by setting MODE to OFF in TIMER_CCx_CTRL. The following figure shows the
output logic for the TIMER/WTIMER module.
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Update
Condition
TIMERn_CNT
TnCCR1[15:0 TIMERn_CCx =
= =
TnCCR0[15:0
]
]
COIST
Output
Compare/
PWM x
Figure 20.15. TIMER/WTIMER Output Logic
TIMERn_TOP
=
= 0
Compare and
PWM config
Compare and
PWM config
Compare and
PWM config
OUTINV
0
TIMn_CCx
1
Reference Manual
TIMER/WTIMER - Timer/Counter
662. In compare
Overflow
Underflow
Compare Match x
TIMn_CC0
TIMn_CC1
TIMn_CC2
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