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/
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Nations Technologies Inc.
Tel
:
+86-755-86309900
:
Address: Nations Tower, #109 Baoshen Road, Hi-tech Park North.
Nanshan District, Shenzhen, 518057, P.R.China
Figure 11-24 Clearing the OCxREF of TIMx
11.3.13
Complementary outputs with dead-time insertion
Advanced-control timer can output two complementary signals, and manage the switching-off and switching-on of
outputs. This is called dead-time. User should adjust dead-time depending on the devices connected to the outputs
and their characteristics.
User can select the polarity of outputs by setting TIMx_CCEN.CCxP and TIMx_CCEN.CCxNP. And this selection
is independently for each output.
User can control the complementary signals OCx and OCxN by setting the combination of several control bits, which
are
TIMx_CCEN.CCxEN,
TIMx_CCEN.CCxNEN,
TIMx_BKDT.MOEN,
TIMx_CTRL2.OIx,
TIMx_CTRL2.OIxN, TIMx_BKDT.OSSI, and TIMx_BKDT.OSSR. When switching to the IDLE state, the dead-
time will be activated.
If user set TIMx_CCEN.CCxEN and TIMx_CCEN.CCxNEN at the same time, a dead-time will be insert. If there is
a break circuit, the TIMx_BKDT.MOEN should be set too. There are 10-bit dead-time generators for each channel.
Reference waveform OCxREF can generates 2 outputs OCx and OCxN. And if OCx and OCxN are active high, the
OCx ouput signal is the same as the reference signal and the OCxN output signal is the opposite of the reference
signal. However, OCx output signal will be delayed relative to the reference rising edge and the OCxN output signal
will be delayed relative to the reference falling edge. If the delay is greater than the width of the active OCx or OCxN
output, the corresponding pulse will not generated.
The relationships between the output signals of the dead-time generator and the reference signal OCxREF are as
follow.
Assume that TIMx_CCEN.CCxP=0, TIMx_CCEN.CCxNP=0, TIMx_BKDT.MOEN=1, TIMx_CCEN.CCxEN=1,
(CCDATx)
Counter(CNT)
ETRF
ETRF becomes
high
OCxREF
(OCxCEN=
'
0
'
)
OCxREF
(OCxCEN=
'1'
)
ETRF
still
high