Functional Description
7-14
ADSP-214xx SHARC Processor Hardware Reference
required, provided the change is done a few cycles before the next period
change.
Complementary Outputs
The PWM controller can be operatde in paired or non paired mode
(
PWMCTLx
register).
In non paired mode (default) both outputs (high and low side) are driven
independently. Since paired mode drives the output logic of the PWM in
a complementary fashion (low side = /high side), this feature may be use-
ful in PWM bridge applications.
Crossover
The
PWMSEG3–0
registers contain two bits (
AHAL_XOVR
and
BHBL_XOVR
), one
for each PWM output. If crossover mode is enabled for any pair of PWM
signals, the high-side PWM signal from the timing unit (for example,
AH
)
is diverted to the associated low side output of the output control unit so
that the signal ultimately appears at the
AL
pin.
The corresponding low side output of the timing unit is also diverted to
the complementary high side output of the output control unit so that the
signal appears at the
AH
pin. Following a reset, the two crossover bits are
cleared so that the crossover mode is disabled on both pairs of PWM sig-
nals. Even though crossover is considered an output control feature, dead
time insertion occurs after crossover transitions to eliminate
shoot-through safety issues.
Note that crossover mode does not work if:
1. One signal of
PWM_AL
–
PWM_AH
or
PWM_BL
–
PWM_BH
is disabled.
2.
PWM_AL
and
PWM_AH
or
PWM_BL
and
PWM_BH
have different polarity
settings from
PWMPOLx
registers.
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Содержание SHARC ADSP-214 Series
Страница 60: ...Contents lx ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Страница 72: ...Notation Conventions lxxii ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Страница 130: ...Programming Model 2 52 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Страница 264: ...Programming Models 3 134 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Страница 290: ...Programming Model 4 26 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Страница 296: ...Programming Model 5 6 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Страница 396: ...Effect Latency 7 28 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Страница 520: ...Programming Model 10 62 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Страница 616: ...Debug Features 14 22 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Страница 656: ...Programming Model 15 40 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Страница 714: ...Programming Model 19 10 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Страница 1132: ...Register Listing A 306 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Страница 1192: ...Index I 34 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...