mc9s12xd256 Freescale Semiconductor, Inc, mc9s12xd256 Datasheet - Page 949

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

DDRH[7:0]
RDRH[7:0]
Reset
Reset
Field
23.0.5.49 Port H Reduced Drive Register (RDRH)
Read: Anytime.
Write: Anytime.
This register configures the drive strength of each Port H output pin as either full or reduced. If the
port is used as input this bit is ignored.
Field
23.0.5.50 Port H Pull Device Enable Register (PERH)
Read: Anytime.
Write: Anytime.
This register configures whether a pull-up or a pull-down device is activated, if the port is used as
input. This bit has no effect if the port is used as output. Out of reset no pull device is enabled.
7–0
7–0
W
W
R
R
RDRH7
PERH7
Data Direction Port H
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
Reduced Drive Port H
0 Full drive strength at output.
1 Associated pin drives at about 1/6 of the full drive strength.
7
0
7
0
on PTH or PTIH registers, when changing the DDRH register.
RDRH6
PERH6
Figure 23-52. Port H Pull Device Enable Register (PERH)
0
0
6
6
Figure 23-51. Port H Reduced Drive Register (RDRH)
Table 23-45. DDRH Field Descriptions
Table 23-46. RDRH Field Descriptions
RDRH5
PERH5
5
0
5
0
RDRH4
PERH4
0
0
4
4
Description
Description
RDRH3
PERH3
3
0
3
0
RDRH2
PERH2
0
0
2
2
RDRH1
PERH1
1
0
1
0
RDRH0
PERH0
0
0
0
0