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Chapter 2 Port Integration Module (S12XEPIMV1)
MC9S12XE-Family Reference Manual Rev. 1.07
Freescale Semiconductor
109
2.3.14
S12X_EBI ports Reduced Drive Register (RDRIV)
This register is used to select reduced drive for the pins associated with the S12X_EBI ports A, B, C, D,
E, and K. If enabled, the pins drive at about 1/6 of the full drive strength. The reduced drive function is
independent of which function is being used on a particular pin.
4
PUPEE
Pull-up Port E Enable
—Enable pull-up devices on all Port E input pins except on pins 5 and 6 which have pull-down
devices only enabled during reset. This bit has no effect on these pins.
This bit configures whether pull-up devices are activated, if the pins are used as inputs. This bit has no effect if the
pins are used as outputs. Out of reset the pull-up devices are enabled.
1 Pull-up devices enabled.
0 Pull-up devices disabled.
3
PUPDE
Pull-up Port D Enable
—Enable pull-up devices on all Port D input pins
This bit configures whether pull-up devices are activated, if the pins are used as inputs. This bit has no effect if the
pins are used as outputs. Out of reset the pull-up devices are disabled.
1 Pull-up devices enabled.
0 Pull-up devices disabled.
2
PUPCE
Pull-up Port C Enable
—Enable pull-up devices on all Port C input pins
This bit configures whether pull-up devices are activated, if the pins are used as inputs. This bit has no effect if the
pins are used as outputs. Out of reset the pull-up devices are disabled.
1 Pull-up devices enabled.
0 Pull-up devices disabled.
1
PUPBE
Pull-up Port B Enable
—Enable pull-up devices on all Port B input pins
This bit configures whether pull-up devices are activated, if the pins are used as inputs. This bit has no effect if the
pins are used as outputs. Out of reset the pull-up devices are disabled.
1 Pull-up devices enabled.
0 Pull-up devices disabled.
0
PUPAE
Pull-up Port A Enable
—Enable pull-up devices on all Port A input pins
This bit configures whether pull-up devices are activated, if the pins are used as inputs. This bit has no effect if the
pins are used as outputs. Out of reset the pull-up devices are disabled.
1 Pull-up devices enabled.
0 Pull-up devices disabled.
Address 0x000D (PRR)
Access: User read/write
1
1
Read: Anytime. In emulation modes, read operations will return the data from the external bus, in all other modes the data
source is depending on the data direction value.
Write: Anytime. In emulation modes, write operations will also be directed to the external bus.
7
6
5
4
3
2
1
0
R
RDPK
0
0
RDPE
RDPD
RDPC
RDPB
RDPA
W
Reset
0
0
0
0
0
0
0
0
= Unimplemented or Reserved
Figure 2-12. S12X_EBI ports Reduced Drive Register (RDRIV)
Table 2-13. PUCR Register Field Descriptions (continued)
Field
Description