Datasheet

Chapter 23 DQ256 Port Integration Module (S12XDQ256PIMV2)
MC9S12XDP512 Data Sheet, Rev. 2.21
944 Freescale Semiconductor
23.0.5.40 Port P Data Direction Register (DDRP)
Read: Anytime.
Write: Anytime.
This register configures each port P pin as either input or output.
If the associated PWM channel or SPI module is enabled this register has no effect on the pins.
The PWM forces the I/O state to be an output for each port line associated with an enabled PWM7–0
channel. Channel 7 can force the pin to input if the shutdown feature is enabled. Refer to PWM section for
details.
If SPI is enabled, the SPI determines the pin direction. Refer to SPI section for details.
The DDRP bits revert to controlling the I/O direction of a pin when the associated peripherals are disabled.
23.0.5.41 Port P Reduced Drive Register (RDRP)
Read: Anytime.
Write: Anytime.
This register configures the drive strength of each port P output pin as either full or reduced. If the port is
used as input this bit is ignored.
76543210
R
DDRP7 DDRP6 DDRP5 DDRP4 DDRP3 DDRP2 DDRP1 DDRP0
W
Reset 00000000
Figure 23-42. Port P Data Direction Register (DDRP)
Table 23-39. DDRP Field Descriptions
Field Description
7–0
DDRP[7:0]
Data Direction Port P
0 Associated pin is configured as input.
1 Associated pin is configured as output.
Note: Due to internal synchronization circuits, it can take up to 2 bus clock cycles until the correct value is read
on PTP or PTIP registers, when changing the DDRP register.
76543210
R
RDRP7 RDRP6 RDRP5 RDRP4 RDRP3 RDRP2 RDRP1 RDRP0
W
Reset 00000000
Figure 23-43. Port P Reduced Drive Register (RDRP)