15.4.3.5.2 Output Control PCI Blocks

The three output control type PCI blocks are provided to place the PWM outputs in a predetermined state. The blocks are prioritized in the following order, along with further details shown in Complementary Output Mode and Output Override in Push-Pull and Independent Modes:

1. Fault
2. Current Limit
3. Feed-Forward

The Fault PCI block has the highest priority of the PCI blocks and will dictate the state of the outputs when the block is used. A Fault condition is generally considered catastrophic and is typically cleared with software.

The Current Limit PCI block was intended for use with current limit sensing circuitry, either for protection or use as a control loop. Leading-Edge Blanking (LEB) is typically used to ignore switching transients in current sensing applications. See Leading-Edge Blanking for details on LEB.

The Feed-Forward PCI block is intended for use as a control loop for power supply applications. If the sensing circuitry detects a rapid change in load conditions, the system can be configured to take immediate action without having to wait until the next PWM cycle to react.

Once a ‘PCI active’ signal is asserted, the value stored in the xDAT[1:0] bits (x = FLT, CL or FF) will be applied immediately to the pins. xDAT bits are located in the PGxIOCON2 register.