Value
OTMX[3]
OTMX[2]
OTMX[1]
OTMX[0]
0x2
CC0
CC0
CC0
CC0
0x3
CC1
CC1
CC1
CC0
The dead-time insertion (DTI)
unit generates OFF time with the non-inverted low side (LS) and inverted
high side (HS) of the wave generator output forced at low level. This OFF time is called dead time. Dead-
time insertion ensures that the LS and HS will never switch simultaneously.
The DTI stage consists of four equal dead-time insertion generators; one for each of the first four
compare channels.
shows the block diagram of one DTI generator. The four channels have
a common register which controls the dead time, which is independent of high side and low side setting.
Figure 36-33. Dead-Time Generator Block Diagram
Dead Time Generator
Edge Detect
D
Q
= 0
"DTLS"
(To PORT)
"DTHS"
(To PORT)
Counter
EN
LOAD
OTMX output
DTLS
DTHS
As shown in
, the 8-bit dead-time counter is decremented by one for each peripheral clock
cycle until it reaches zero. A non-zero counter value will force both the low side and high side outputs into
their OFF state. When the output matrix (OTMX) output changes, the dead-time counter is reloaded
according to the edge of the input. When the output changes from low to high (positive edge) it initiates a
counter reload of the DTLS register. When the output changes from high to low (negative edge) it reloads
the DTHS register.
Figure 36-34. Dead-Time Generator Timing Diagram
"dti_cnt"
"OTMX output"
"DTLS"
"DTHS"
t
DTILS
t
DTIHS
T
t
P
Atmel SAM L22G / L22J / L22N [DATASHEET]
Atmel-42402E-SAM L22G / L22J / L22N_Datasheet_Complete-07/2016
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