NXP Semiconductors MPC5644A, Reference Manual, Page: 401 / 1735

System Integration Unit (SIU)
MPC5644A Microcontroller Reference Manual, Rev. 6
Freescale Semiconductor 401
Table 16-18. SIU_PCR field description
Field Description
— Reserved fields are indicated by shading in the register maps.
PA Pin assignment
Selects the function of a multiplexed pad.
OBE
1,2
Output buffer enable
Enables the pad as an output and drives the output buffer enable signal.
0 Disable output buffer for the pad.
1 Enable output buffer for the pad is enabled.
IBE
1,2
Input buffer enable
Enables the pad as an input and drives the input buffer enable signal.
0 Disable input buffer for the pad.
1 Enable input buffer for the pad is enabled.
For all PCRs where GPIO function is available on the pin, if the pin is configured as an output and the
IBE bit is set, the actual value of the pin will be reflected in the corresponding GPDI
x _ x register. Negating
the IBE bit when the pin is configured as an output will reduce noise and power consumption.
DSC
3
Drive strength control
Controls the pad drive strength. Drive strength control pertains to pins with the fast I/O pad type.
00 10 pF drive strength
01 20 pF drive strength
10 30 pF drive strength
11 50 pF drive strength
ODE
3
Open drain output enable
Controls output driver configuration for the pads. Either open drain or push/pull driver configurations can
be selected. This feature applies to output pins only.
0 Disable open drain for the pad (push/pull driver enabled).
1 Enable open drain for the pad.
PA value
1
1
Depending on the register, the PA field size can vary in length.
For PA fields having fewer than four bits, remove the
appropriate number of leading zeroes from these values.
Pin function
0b0001 P Primary function
0b0010 A1 Alternate function 1
0b0100 A2 Alternate function 2
0b1000 A3 Alternate function 3
0b0000 G GPIO