SPRUHM8K December 2013 – May 2024 TMS320F28374D , TMS320F28375D , TMS320F28376D , TMS320F28377D , TMS320F28377D-EP , TMS320F28377D-Q1 , TMS320F28378D , TMS320F28379D , TMS320F28379D-Q1
Since the ramp generator makes state changes on every rising edge of EPWMSYNCPER and COMPHSTS, the following behavior can be expected on instances when these two events occur simultaneously or very close together.
Case 1: COMPHSTS rising edge occurs one or
more cycles before EPWMSYNCPER rising edge.
RAMPSTS stops decrementing on
COMPHSTS rising edge event. RAMPSTS starts decrementing on EPWMSYNCPER rising edge event when RAMPDLYA reaches 0.
Case 2: COMPHSTS rising edge occurs simultaneously as EPWMSYNCPER rising edge.
EPWMSYNCPER rising edge event
takes precedence and RAMPSTS starts decrementing when RAMPDLYA reaches 0. COMPHSTS rising
edge event is ignored and does not halt RAMPSTS.
Case 2: COMPHSTS rising edge occurs simultaneously as EPWMSYNCPER rising edge.
COMPHSTS rising edge event takes precedence and RAMPSTS stops decrementing. EPWMSYNCPER rising edge event is ignored and does not start decrementing RAMPSTS when RAMPDLYA reaches 0.
Case 3: COMPHSTS rising edge occurs one or
more cycles after EPWMSYNCPER rising edge but before RAMPDLYA reaches 0.
RAMPSTS does not decrement when RAMPDLYA reaches 0.
Case 4: COMPHSTS rising edge occurs
simultaneously as RAMPDLYA reaches 0 from EPWMSYNCPER rising edge.
RAMPSTS does not
decrement.
This behavior is also illustrated in Figure 13-5.