mc9s12e256 Freescale Semiconductor, Inc, mc9s12e256 Datasheet - Page 137

• Manufacturer Part Number: mc9s12e256
• Description: Hcs12 Microcontrollers 16-bit Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

3.3.2.2
Read: Anytime. Write: Never, writes to this register have no effect.
This register always reads back the status of the associated pins.
3.3.2.3
Read: Anytime. Write: Anytime.
This register configures port pins PM[7:3] and PM[1:0] as either input or output.
If the IIC is enabled, the IIC controls the SCL and SDA I/O direction, and the corresponding DDRM[7:6]
bits have no effect on their I/O direction. Refer to
details.
If the SCI2 transmitter is enabled, the I/O direction of the transmit pin TXD2 is controlled by SCI2, and
the DDRM5 bit has no effect. If the SCI2 receiver is enabled, the I/O direction of the receive pin RXD2 is
controlled by SCI2, and the DDRM4 bit has no effect. Refer to
Interface (SCIV4)”
If the DAC1 or DAC0 channel is enabled, the associated pin DAO1 or DAO0 is forced to be output, and
the associated DDRM1 or DDRM0 bit has no effect.
The DDRM bits do not change to reflect the pin I/O direction when not being used as GPIO. The
DDRM[7:3]; DDRM[1:0] bits revert to controlling the I/O direction of the pins when the associated IIC,
SCI, or DAC1/0 function are disabled.
Freescale Semiconductor
DDRM[7:3,
7:3, 1:0
Reset
Reset
Field
1:0]
W
W
R
R
DDRM7
PTIM7
Data Direction Port M
0 Associated pin is configured as input.
1 Associated pin is configured as output.
Port M Input Register (PTIM)
Port M Data Direction Register (DDRM)
u
0
7
7
for further details.
= Reserved or Unimplemented
= Reserved or Unimplemented
DDRM6
PTIM6
u
0
6
6
Figure 3-12. Port M Data Direction Register (DDRM)
Figure 3-11. Port M Input Register (PTIM)
Table 3-9. DDRM Field Descriptions
DDRM5
PTIM5
MC9S12E256 Data Sheet, Rev. 1.08
u
0
5
5
DDRM4
PTIM4
u
0
Chapter 10, “Inter-Integrated Circuit (IICV2)”
4
4
Description
u = Unaffected by reset
DDRM3
PTIM3
3
u
3
0
Chapter 8, “Serial Communication
Chapter 3 Port Integration Module (PIM9E256V1)
0
0
0
0
2
2
DDRM1
PTIM1
u
0
1
1
DDRM0
PTIM0
for
u
0
0
0
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