Enhanced Queued Analog-to-Digital Converter (eQADC)MPC5566 Microcontroller Reference Manual, Rev. 219-76 Freescale Semiconductor19.4.3.6.4 Trigger Overrun StatusWhen a CFIFO is configured for edge or level trigger mode and is in a TRIGGERED state, an additionaltrigger event for the same CFIFO causes a trigger overrun:1. The trigger overrun bit for the CFIFO is set (EQADC_FISRn[TORFn] = 1)2. The EQADC_CFCRn[TORIE] and EQADC_FISRn[TORF] assert3. The eQADC generates a trigger overrun interrupt request.Refer to the following sections for more information:Section 19.3.2.8, “eQADC FIFO and Interrupt Status Registers 0–5 (EQADC_FISRn)”Section 19.3.2.6, “eQADC CFIFO Control Registers 0–5 (EQADC_CFCRn)”For CFIFOs configured for level trigger mode, a trigger overrun event is detected only when the gatecloses and reopens during a single serial command transmission as shown in Figure 19-40.Figure 19-40. Trigger Overrun on Level Trigger Mode CFIFOsNOTEThe trigger overrun flag is not set for CFIFOs configured for softwaretrigger mode.19.4.3.6.5 Command Sequence Non-Coherency DetectionThe eQADC provides a mechanism to indicate if a command sequence has been completely executedwithout interruptions. A command sequence is defined as a group of consecutive commands bound for thesame ADC and it is expected to be executed without interruptions. A command sequence is coherent if itscommands are executed in order without interruptions. Because commands are stored in the ADC’scommand buffers before being executed in the eQADC, a command sequence is coherent if, while it istransferring commands to an on-chip ADC command buffer, the buffer is only fed with commands fromthat sequence without ever becoming empty.A command sequence starts when:• A CFIFO in TRIGGERED state transfers its first command to an on-chip ADC.Command transmissionthrough eQADC SSICFIFO statusTORFCommand 1 Null message Command 2Triggered WFT Triggered TriggeredWFTLow activeLevel triggerIf gate closes during a command transmission, it is onlyrecognized when the transmission ends.1) CFIFO programmed to ‘continuous-scan low level gated external trigger mode’.2) Command 2 has its ABORT_ST bit negated.Assumptions:3) There are no other CFIFOs using the serial interface.WFT = Waiting for Trigger
