Datasheet

Bus Control and Input/Output (I/O)
M68HC12B Family Data Sheet, Rev. 9.1
92 Freescale Semiconductor
6.3.9 Reduced Drive of I/O Lines
Read: Anytime, if register is in the map
Write: Once in normal modes; anytime, except the first time, in special modes
These bits select reduced drive for the associated port pins. This gives reduced power consumption and
reduced radio frequency interference (RFI) with a slight increase in transition time (depending on loading).
The reduced drive function is independent of which function is being used on a particular port. This
register is not in the map in peripheral mode.
RDPE — Reduced Drive of Port E Bit
1 = Reduced drive for all port E output pins
0 = Full drive for all port E output pins
RDPB — Reduced Drive of Port B Bit
1 = Reduced drive for all port B output pins
0 = Full drive for all port B output pins
RDPA — Reduced Drive of Port A Bit
1 = Reduced drive for all port A output pins
0 = Full drive for all port A output pins
Address:
$000D
Bit 7654321Bit 0
Read:0000
RDPE
0
RDPB RDPA
Write:
Reset:00000000
= Unimplemented
Figure 6-9. Reduced Drive of I/O Lines (RDRIV)