Texas Instruments TMS320x28xx 사용자 설명서
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TBCTR
EPWMxA
EPWMxB
TBPRD
value
CB
CA
P
P
P
P
CB
CA
P
P
Action-Qualifier (AQ) Submodule
Figure 2-22. Up, Single Edge Asymmetric Waveform With Independent Modulation on EPWMxA and
EPWMxB—Active Low
A
PWM period = (TBPRD + 1 )
×
T
TBCLK
B
Duty modulation for EPWMxA is set by CMPA, and is active low (that is, the low time duty is proportional to CMPA).
C
Duty modulation for EPWMxB is set by CMPB and is active low (that is, the low time duty is proportional to CMPB).
D
The Do Nothing actions ( X ) are shown for completeness here, but will not be shown on subsequent diagrams.
E
Actions at zero and period, although appearing to occur concurrently, are actually separated by one TBCLK period.
TBCTR wraps from period to 0000.
TBCTR wraps from period to 0000.
contains a code sample showing initialization and run time for the waveforms in
44
ePWM Submodules
SPRU791D – November 2004 – Revised October 2007