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If interrupt occurs, corresponded bit of Channel-x interrupt register(CHn_IR) bit is set and
PWM channel-n interrupt signal is generated. All CHn_IR is cleared by channel-n interrupt
clear register(CHn_ICR) and then PWM channel-n interrupt signal is cleared.
18.3.5
Dead zone generation
Each PWM channel can output two complementary signals with dead zone time and it can be
enabled by Channel-n Dead Zone Enable Register(CHn_DZER). Only 4 channels can be
enabled because there are 8 PWM output pins. Channel 0 and 1 are a pair, channel 2 and 3
are a pair, channel 4 and 5 are a pair, and channel 6 and 7 are a pair. If users want to use
channel-0 dead zone generation, channel-1 should be disabled. If channel 0 and 1 dead zone
generation are enabled both, all outputs are 0. In that case, users should choose 1 channel.
Dead zone time are generated by the value of Channel-n Dead Zone Counter Register(DZCR).
The dead zone counter counts up to value of DZCR. During the dead zone time, both
complementary signals are both 0. Users have to adjust the signal depending on the devices
that are connected to the outputs and their characteristics. If DZCR is bigger than the limit
register, main output signal is toggled 0 to1 and then 1 to 0 while 1 PWMCLK and inverted
output signal is always 0.
Figure 37 shows two complementary PWM outputs with dead zone time. During dead zone
time, both outputs are 0. Figure 38 shows a more detailed timing with dead zone counter.
The dead zone counter and the Timer/Counter starts to count together and PWM output is 0
until dead zone counter is reached to value of dead zone counter register. The PWM output
becomes 1 and 0 when the Timer/Counter is reached to value of match register. The
inverted PWM output is also 0 until dead zone counter is reached to value of dead zone
counter register. Then inverted PWM output becomes 1 after dead zone counter is reached
to the value of dead zone counter register.
PWM
output
Inverted PWM
output
W7500 Datasheet Version1.0.0
Dead zone
Dead zone
time
time
Figure 37 PWM waveform with dead zone time
Dead zone
Dead zone
time
time
Dead zone
time
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