S912XEG128J2MAA Datasheet, PDF (146/1324 Pages) Freescale Semiconductor, Inc – Microcontrollers

Chapter 2 Port Integration Module (S12XEPIMV1)
Table 2-51. DDRH Register Field Descriptions (continued)
Field
1
DDRH
0
DDRH
Description
Port H data direction—
This register controls the data direction of pin 1.
The enabled SCI6 forces the I/O state to be an output. Depending on the configuration of the enabled routed SPI1
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.
Port H data direction—
This register controls the data direction of pin 0.
The enabled SCI6 forces the I/O state to be an input. Depending on the configuration of the enabled routed SPI1
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.
NOTE
Due to internal synchronization circuits, it can take up to 2 bus clock cycles
until the correct value is read on PTH or PTIH registers, when changing the
DDRH register.
2.3.56 Port H Reduced Drive Register (RDRH)
Address 0x0263
R
W
Reset
7
RDRH7
0
1. Read: Anytime.
Write: Anytime.
6
RDRH6
5
RDRH5
4
RDRH4
3
RDRH3
2
RDRH2
0
0
0
0
0
Figure 2-54. Port H Reduced Drive Register (RDRH)
Access: User read/write⁽¹⁾
1
0
RDRH1
RDRH0
0
0
Table 2-52. RDRH Register Field Descriptions
Field
Description
7-0
RDRH
Port H reduced drive—Select reduced drive for outputs
This register configures the drive strength of output pins 7 through 0 as either full or reduced independent of the
function used on the pins. If a pin is used as input this bit has no effect.
1 Reduced drive selected (approx. 1/5 of the full drive strength).
0 Full drive strength enabled.
MC9S12XE-Family Reference Manual Rev. 1.25
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Freescale Semiconductor