SLUSB72D March 2013 – April 2021 UCD3138064
In order to allow a flexible way of mapping several fault triggering sources to all the DPWMs channels, the UCD3138x provides an extensive array of multiplexers that are united under the name Fault Mux module.
The Fault Mux Module supports the following types of mapping between all the sources of fault and all the different fault response mechanisms inside each DPWM module.
The Fault Mux Module provides a multitude of fault protection functions within the UCD3138x high-speed loop (Front End Control, Filter, DPWM and Loop Mux modules). The Fault Mux Module allows highly configurable fault generation based on digital comparators, high-speed analog comparators and external fault pins. Each of the fault inputs to the DPWM modules can be configured to one or any combination of the fault events provided in the Fault Mux Module.
Each one of the DPWM engines has four fault modules. The modules are called CBC fault module, AB fault module, A fault module and B fault module.
The internal circuitry in all the four fault modules is identical, and the difference between the modules is limited to the way the modules are attached to the DPWMs.
All fault modules provide immediate fault detection but only once per DPWM switching cycle. Each one of the fault modules own a separate max_count and the fault flag will be set only if sequential cycle-by-cycle fault count exceeds max_count.
Once the fault flag is set, DPWMs need to be disabled by DPWM_EN going low in order to clear the fault flags. Please note, all four Fault Modules share the same DPWM_EN control, all fault flags (output of Fault Modules) will be cleared simultaneously.
All four Fault Modules share the same global FAULT_EN as well. Therefore a specific Fault Module cannot be enabled/ disabled separately.
Unlike Fault Modules, only one Cycle by Cycle block is available in each DPWM module.
The Cycle by Cycle block works in conjunction with CBC Fault Module and enables DPWM reaction to signals arriving from the Analog Peak current mode (PCM) module.
The Fault Mux Module supports the following basic functions: