PXR40RM Datasheet, PDF (209/1434 Pages) Freescale Semiconductor, Inc – PXR40 Microcontroller

System Integration Unit (SIU)
There are a number of input signals on the device that have multiple external pins as input sources. Only
one input source can be active at any time for these pins. To achieve this, there is a pre-defined priority for
the PCR registers controlling these pins, which is used to mux the input sources and allow only one active
input. The multiple source inputs with PCR priority is given in Table 7-21.
Table 7-21. PCR priority for multiple source inputs
Function
IRQ0
IRQ1
IRQ2
IRQ3
IRQ4
IRQ5
PCSB0
SCKC
SINC
PCSC0
SCKD
SIND
PCSD0
CANRXD
TXDA
RXDA
TXDB
RXDB
FR_RX_A
PCR number
highest
priority

lowest
priority
193
450
—
194
451
—
211
452
—
212
453
—
208
454
—
209
455
—
105
203
—
235
109
—
236
108
—
238
110
434
189
470
—
190
472
—
106
469
—
247
194
—
89
83
460
90
84
461
91
462
—
92
463
—
249
458
—
Freescale Semiconductor
PXR40 Microcontroller Reference Manual, Rev. 1
7-27