Freescale Semiconductor MPC5565, Reference Manual

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System Integration Unit (SIU)
MPC5565 Microcontroller Reference Manual, Rev. 1.0
Freescale Semiconductor 6-119
Figure 6-162. DSPI Serial Chaining
Parallel chaining allows the PCS and SCK from one DSPI to be used by more than one external SPI device,
thus reducing pin utilization of the device MCU. In this example, the SOUT and SIN of the two DSPIs
connect to separate external SPI devices, which share a common PCS and SCK.
To support multiple transfer operation of the DSPIs, an input multiplexor is required for the SIN, SS, SCK
IN, and trigger signals of each DSPI. The input source for the SIN input of a DSPI can be a pin or the
SOUT of any of the other three DSPIs. The input source for the SS input of a DSPI can be a pin or the
PCS
X [0] of any of the other three DSPIs. The input source for the SCK input of a DSPI can be a pin or the
SCK output of any of the other three DSPIs. The input source for the trigger input can be the PCSS output
of any of the other three DSPIs. The input source for each DSPI SIN, SS, SCK, and trigger signal is
individually specified in the DSPI input select register (SIU_DISR).
SOUT SOUT
SIN SIN
PCS[0] SS SCK
SCK IN
DSPI A (master)
DSPI B (slave)
SS
SCK IN
SIN
SOUT
External SPI device
MTRIG
Trigger
SOUTB SCKA PCSA[0] SINA