Functional Description
14-26
ADSP-BF50x Blackfin Processor Hardware Reference
Mode Bits (POLARITY and SRMODE)
PWM_POLARITY
and
PWM_SRMODE
are programmable bits of the
PWM_CTRL
register.
The incorrect programming of these two mode-select signals can
have destructive consequences on the external power inverter con-
nected to the PWM unit. Since
PWM_POLARITY
and
PWM_SRMODE
are
software programmable bits, accidental power inverter
shoot-through current may occur from incorrect programming.
Output Enable Function
The
PWM_SEG
register also contains six bits (bits 0 to 5) that can be used to
individually enable or disable each of the six PWM outputs. The PWM
signal of the
AL
pin is enabled by clearing the
AL_EN
bit of the
PWM_SEG
reg-
ister, the
AH_EN
bit controls
AH
, the
BL_EN
bit controls
BL
, the
BH_EN
bit
controls
BH
, the
CL_EN
bit controls
CL
, and the
CH_EN
bit controls the
CH
output. If the associated bit of the
PWM_SEG
register is set, the correspond-
ing PWM output is disabled irrespective of the value of the corresponding
duty cycle register. This PWM output signal will remain in the off state as
long as the corresponding enable/disable bit of the
PWM_SEG
register is set.
This output enable function is implemented after the crossover function.
Following a reset, all six enable bits of the
PWM_SEG
register are cleared so
that all PWM outputs are enabled by default. In a manner identical to the
duty cycle registers, the
PWM_SEG
register is latched on the rising edge of
the
PWM_SYNC
signal so that changes to this register only become effective
at the start of each PWM cycle in single-update mode. In double-update
mode, the
PWM_SEG
register can also be updated at the midpoint of the
PWM cycle.
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 ...