mc9s12e256 Freescale Semiconductor, Inc, mc9s12e256 Datasheet - Page 528

• Manufacturer Part Number: mc9s12e256
• Description: Hcs12 Microcontrollers 16-bit Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

Chapter 18 Multiplexed External Bus Interface (MEBIV3)
18.3.2.11 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.
528
RDRK
RDPE
RDPB
RDPA
Field
7
4
1
0
Reset
W
R
Reduced Drive of Port K
0 All port K output pins have full drive enabled.
1 All port K output pins have reduced drive enabled.
Reduced Drive of Port E
0 All port E output pins have full drive enabled.
1 All port E output pins have reduced drive enabled.
Reduced Drive of Port B
0 All port B output pins have full drive enabled.
1 All port B output pins have reduced drive enabled.
Reduced Drive of Ports A
0 All port A output pins have full drive enabled.
1 All port A output pins have reduced drive enabled.
RDRK
0
7
= Unimplemented or Reserved
0
0
6
Figure 18-16. Reduced Drive Register (RDRIV)
Table 18-10. RDRIV Field Descriptions
MC9S12E256 Data Sheet, Rev. 1.08
0
0
5
RDPE
0
4
Description
3
0
0
2
0
0
Freescale Semiconductor
RDPB
0
1
RDPA
0
0