mc9s12hz256v2 Freescale Semiconductor, Inc, mc9s12hz256v2 Datasheet - Page 592

• Manufacturer Part Number: mc9s12hz256v2
• Description: Hcs12 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

Chapter 21 Multiplexed External Bus Interface (MEBIV3)
This register is not in the on-chip memory map in expanded and special peripheral modes. Therefore, these
accesses will be echoed externally.
21.3.2.11 Reduced Drive Register (RDRIV)
Read: Anytime (provided this register is in the map)
Write: Anytime (provided this register is in the map)
This register is used to select reduced drive for the pins associated with the core ports. This gives reduced
power consumption and reduced RFI with a slight increase in transition time (depending on loading). This
feature would be used on ports which have a light loading. The reduced drive function is independent of
which function is being used on a particular port.
This register is not in the on-chip memory map in expanded and special peripheral modes. Therefore, these
accesses will be echoed externally.
592
PUPKE
PUPEE
PUPBE
PUPAE
Field
7
4
1
0
Reset
W
R
Pull resistors Port K Enable
0 Port K pull resistors are disabled.
1 Enable pull resistors for port K input pins.
Pull resistors Port E Enable
0 Port E pull resistors on bits 7, 4:0 are disabled.
1 Enable pull resistors for port E input pins bits 7, 4:0.
Note: Pins 5 and 6 of port E have pull resistors which are only enabled during reset. This bit has no effect on
Pull resistors Port B Enable
0 Port B pull resistors are disabled.
1 Enable pull resistors for all port B input pins.
Pull resistors Port A Enable
0 Port A pull resistors are disabled.
1 Enable pull resistors for all port A input pins.
RDRK
These bits have no effect when the associated pin(s) are outputs. (The pull
resistors are inactive.)
0
7
these pins.
= Unimplemented or Reserved
0
0
6
Figure 21-15. Reduced Drive Register (RDRIV)
Table 21-9. PUCR Field Descriptions
MC9S12HZ256 Data Sheet, Rev. 2.05
0
0
5
NOTE
RDPE
0
4
Description
3
0
0
2
0
0
Freescale Semiconductor
RDPB
0
1
RDPA
0
0