System Integration Unit (SIU)MPC5566 Microcontroller Reference Manual, Rev. 26-124 Freescale SemiconductorAn example of the multiplexing of an eQADC external trigger input is given in Figure 6-172.Figure 6-172. eQADC External Trigger Input MultiplexingRefer to Section 6.3.1.161, “eQADC Trigger Input Select Register (SIU_ETISR)” for theSIU_ETISR[TSEL0]–SIU_ETISR[TSEL5] bit definitions.6.4.5.2 SIU External Interrupt Input MultiplexingThe sixteen SIU external interrupt inputs can be connected to either an external pin or to serialized outputsignals from a DSPI module. The input source for each SIU external interrupt is individually specified inthe external IRQ input select register (SIU_EIISR).As shown in the figure, the IRQ[0] input of the SIU can be connected to either the IRQ[0]_GPIO[203] pin,the PCSB[0] serial input signal, the PCSC[1] deserialized output signal, or the PCSD[2] deserializedoutput signal. The remaining IRQ inputs are multiplexed in the same manner. The inputs to the IRQ fromeach DSPI module are offset by one so that if more than one DSPI module is connected to the sameexternal device type, a separate interrupt can be generated for each device. This also applies to DSPImodules connected to external devices of different type that have status bits in the same bit location of thedeserialized information.An example of the multiplexing of an SIU external interrupt input is given in Figure 6-173.Figure 6-173. DSPI Serialized Input Multiplexing6.4.5.3 Multiplexed Inputs for DSPI Multiple Transfer OperationEach DSPI module can be combined in a serial or parallel chain (multiple transfer operation). Serialchaining allows SPI operation with an external device that has more bits than one DSPI module.SIU_ETISR[TSEL0]ETRIG[0]GPIO[206]ETRIG[0]_GPIO[111]ETPUA[30] output channelEMIOS[10] output channelIRQ[0]IRQ[0]_GPIO[203]DSPI B[0] serialized inputDSPI C[1] serialized inputDSPI D[2] serialized inputESEL[0]ESEL[1]NOTE: The MPC5566 has DSPI A in addition to B, C, D.
