Datasheet

Chapter 23 DQ256 Port Integration Module (S12XDQ256PIMV2)
MC9S12XDP512 Data Sheet, Rev. 2.21
932 Freescale Semiconductor
23.0.5.19 Port T Data Direction Register (DDRT)
Read: Anytime.
Write: Anytime.
This register configures each port T pin as either input or output.
The ECT forces the I/O state to be an output for each timer port associated with an enabled output compare.
In this case the data direction bits will not change.
The DDRT bits revert to controlling the I/O direction of a pin when the associated timer output compare
is disabled.
The timer input capture always monitors the state of the pin.
23.0.5.20 Port T Reduced Drive Register (RDRT)
Read: Anytime.
Write: Anytime.
Table 23-22. PTIT Field Descriptions
Field Description
7–0
PTIT[7:0]
Port T Input — This register always reads back the buffered state of the associated pins. This can also be used
to detect overload or short circuit conditions on output pins.
76543210
R
DDRT7 DDRT6 DDRT5 DDRT4 DDRT3 DDRT2 DDRT1 DDRT0
W
Reset 00000000
Figure 23-21. Port T Data Direction Register (DDRT)
Table 23-23. DDRT Field Descriptions
Field Description
7–0
DDRT[7:0]
Data Direction Port T
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 PTT or PTIT registers, when changing the DDRT register.
76543210
R
RDRT7 RDRT6 RDRT5 RDRT4 RDRT3 RDRT2 RDRT1 RDRT0
W
Reset 00000000
Figure 23-22. Port T Reduced Drive Register (RDRT)