ADSP-BF50x Blackfin Processor Hardware Reference
14-25
PWM Controller
Switched Reluctance Mode
A general-purpose mode utilizing independent edge placement of upper
and lower signals of each of the three PWM channels is incorporated into
the Three-Phase PWM Timing Unit. This mode is provided for SR motor
operation and is described in detail in
“Switched Reluctance (SR) Mode”
on page 14-31
.
Output Control Unit
The operation of the Output Control Unit is controlled by the 9-bit
read/write
PWM_SEG
register (
on page 14-45
) that controls two distinct
features that are useful in the control of ECMs or BDCMs.
Crossover Feature
The
PWM_SEG
register contains three crossover bits—one for each pair of
PWM outputs. Setting the
AHAL_XOVR
bit of the
PWM_SEG
register enables
crossover mode for the
AH
/
AL
pair of PWM signals, setting
BHBL_XOVR
enables crossover on the
BH
/
BL
pair, and setting
CHCL_XOVR
enables cross-
over on the
CH
/
CL
pair. If crossover mode is enabled for any pair of PWM
signals, the high-side PWM signal (for example,
AH
) from the Three-Phase
PWM Timing Unit 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 Three-Phase PWM Timing
Unit is also diverted to the complementary high-side output of the Out-
put Control Unit so that the signal appears at the
AH
pin. Following a
reset, the three crossover bits are cleared, disabling crossover mode on all
three pairs of PWM signals. Even though crossover is considered an out-
put control feature, dead time insertion occurs after crossover transitions
(as necessary to eliminate shoot-through safety issues).
Summary of Contents for EZ-KIT Lite ADSP-BF506F
Page 50: ...Contents l ADSP BF50x Blackfin Processor Hardware Reference ...
Page 92: ...Development Tools 1 30 ADSP BF50x Blackfin Processor Hardware Reference ...
Page 110: ...Interface Overview 3 12 ADSP BF50x Blackfin Processor Hardware Reference ...
Page 236: ...Internal Flash Memory Control Registers 6 92 ADSP BF50x Blackfin Processor Hardware Reference ...
Page 650: ...Programming Examples 15 56 ADSP BF50x Blackfin Processor Hardware Reference ...
Page 804: ...Programming Examples 17 92 ADSP BF50x Blackfin Processor Hardware Reference ...
Page 1194: ...Programming Examples 24 90 ADSP BF50x Blackfin Processor Hardware Reference ...
Page 1256: ...ACM Registers A 50 ADSP BF50x Blackfin Processor Hardware Reference ...
Page 1264: ...Boundary Scan Architecture B 8 ADSP BF50x Blackfin Processor Hardware Reference ...