Timing Generation
CLIM/
CBC
Fault
Mux
DPWM
DPWMC
DPWMB
DPWMA
Counter Module
(CBC_MAX_COUNT)
Fault Enable
(CBC_FAULT_EN)
A and B both off
Counter Module
(AB_MAX_COUNT)
FAULT
AB
Counter Module
(A_MAX_COUNT)
FAULT
A
Counter Module
(B_MAX_COUNT)
FAULT
B
A off
B off
Fault Enable
(ALL_FAULT_EN)
Edge Generation
CBC Blanking
(Blanking Registers)
DPWM Fault Action
231
SNIU028A – February 2016 – Revised April 2016
Copyright © 2016, Texas Instruments Incorporated
Fault Mux
Almost any fault detection circuit can be connected to any fault input on any DPWM. The only exception is
the Analog Peak Current mode, which can only be connected to the CLIM fault input:
FaultMuxRegs.DPWM0CLIM.bit.ANALOG_PCM_EN = 1;
6.8
DPWM Fault Action
The final section in the fault chain is the fault action, which takes place in the DPWM module. Here is a
drawing showing the main points of fault action:
Figure 6-3. UCD3138 DPWM Fault Action
This drawing fits in with the overview of the DPWM in
. The portion expanded here is the fault
handler portion. The connection of the CLIM/CBC signal to the Timing Generation Module is also shown.
For information on the effect of CLIM/CBC in the timing module, see
. The bits described in
that section affect the CLIM/CBC signal which is sent to the Timing Generator.
also describes
the Blanking Registers in the DPWM, which permit blanking of the CLIM/CBC signal to the
Timing
Generation section
. These registers are used to prevent switching noise from causing false triggers of the
CBC logic. They can also be used to synchronize CBC triggers between DPWMs with different on-times.
The blanking registers affect different edges depending on topology. The effects are as follows:
•
For normal and resonant modes, blanking A and B windows are applied to PWM-A only
•
For triangular mode, blanking A and B windows are applied to PWM-B only
•
For all other modes, blanking A and B windows are applied to PWM-A and PWM-B respectively