![](http://datasheet.mmic.net.cn/370000/P3S12XEP100J1CAGR_datasheet_16728231/P3S12XEP100J1CAGR_127.png)
Chapter 2 Port Integration Module (S12XEPIMV1)
MC9S12XE-Family Reference Manual Rev. 1.07
Freescale Semiconductor
127
NOTE
Due to internal synchronization circuits, it can take up to 2 bus clock cycles
untilthecorrectvalueisreadonPTMorPTIMregisters,whenchangingthe
DDRM register.
4
DDRM
Port M data direction
—
This register controls the data direction of pin 4.
The enabled CAN2, routed CAN0, orrouted CAN4forces the I/O stateto be an input. Depending on the configuration
of the enabled routed SPI0 this pin will be forced to be input or output.In those cases the data direction bits will not
change. The DDRM bits revert to controlling the I/O direction of a pin when the associated peripheral module is
disabled.
1 Associated pin is configured as output.
0 Associated pin is configured as input.
3
DDRM
Port M data direction
—
This register controls the data direction of pin 3.
The enabled CAN1 or routed CAN0 forces the I/O state to be an output. Depending on the configuration of the
enabled routed SPI0 this pin will be forced to be input or output. In those cases the data direction bits will not change.
The DDRM bits revert to controlling the I/O direction of a pin when the associated peripheral module is disabled.
1 Associated pin is configured as output.
0 Associated pin is configured as input.
2
DDRM
Port M data direction
—
This register controls the data direction of pin 2.
The enabled CAN1 or routed CAN0 forces the I/O state to be an input. Depending on the configuration of the enabled
routed SPI0 this pin will be forced to be input or output.In those cases the data direction bits will not change. The
DDRM bits revert to controlling the I/O direction of a pin when the associated peripheral module is disabled.
1 Associated pin is configured as output.
0 Associated pin is configured as input.
1
DDRM
Port M data direction
—
This register controls the data direction of pin 1.
The enabled CAN0 forces the I/O state to be an output. In those cases the data direction bits will not change. The
DDRM bits revert to controlling the I/O direction of a pin when the associated peripheral module is disabled.
1 Associated pin is configured as output.
0 Associated pin is configured as input.
0
DDRM
Port M data direction
—
This register controls the data direction of pin 0.
The enabled CAN0 forces the I/O state to be an input. In those cases the data direction bits will not change. The
DDRM bits revert to controlling the I/O direction of a pin when the associated peripheral module is disabled.
1 Associated pin is configured as output.
0 Associated pin is configured as input.
Table 2-34. DDRM Register Field Descriptions (continued)
Field
Description