mc9s12xd256 Freescale Semiconductor, Inc, mc9s12xd256 Datasheet - Page 845

• Manufacturer Part Number: mc9s12xd256
• Description: Hcs12x Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

22.3.2.25 Port S Data Direction Register (DDRS)
Read: Anytime.
Write: Anytime.
This register configures each port S pin as either input or output.
If SPI0 is enabled, the SPI0 determines the pin direction. Refer to SPI section for details.
If the associated SCI transmit or receive channel is enabled this register has no effect on the pins. The pin
is forced to be an output if a SCI transmit channel is enabled, it is forced to be an input if the SCI receive
channel is enabled.
The DDRS bits revert to controlling the I/O direction of a pin when the associated channel is disabled.
Freescale Semiconductor
DDRS[7:0]
Reset
Field
7–0
W
R
DDRS7
Data Direction Port S
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
0
7
on PTS or PTIS registers, when changing the DDRS register.
DDRS6
0
6
Figure 22-27. Port S Data Direction Register (DDRS)
Table 22-27. DDRS Field Descriptions
DDRS5
MC9S12XDP512 Data Sheet, Rev. 2.17
0
5
DDRS4
0
4
Description
Chapter 22 DP512 Port Integration Module (S12XDP512PIMV2)
DDRS3
0
3
DDRS2
0
2
DDRS1
0
1
DDRS0
0
0
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