Freescale Semiconductor, Inc.
Bus Control and Input/Output
Registers
PUPH — Pull-Up or Pull-Down Port H Enable
0 = Port H resistive loads (pull-ups or pull-downs) are disabled.
1 = Enable resistive load devices (pull-ups or pull-downs) for all
port H input pins.
PUPE — Pull-Up Port E Enable
0 = Port E pull-ups on PE7, PE3, PE2, PE1 and PE0 are disabled.
1 = Enable pull-up devices for port E input pins PE7, PE3, PE2,
PE1 and PE0.
When this bit is set port E input pins 7, 3, 2, 1 and 0 have an active
pull-up device.
PUPB — Pull-Up Port B Enable
0 = Port B pull-ups are disabled.
1 = Enable pull-up devices for all port B input pins.
This bit has no effect if port B is being used as part of the address/data
bus (the pull-ups are inactive).
PUPA — Pull-Up Port A Enable
0 = Port A pull-ups are disabled.
1 = Enable pull-up devices for all port A input pins.
This bit has no effect if port B is being used as part of the address/data
bus (the pull-ups are inactive).
RDRIV — Reduced Drive of I/O Lines
$000D
Bit 7
RDPK
0
6
RDPJ
0
5
RDPH
0
4
RDPE
0
3
0
0
2
0
0
1
RDPB
0
Bit 0
RDPA
0
RESET:
These bits select reduced drive for the associated port pins. This
gives reduced power consumption and reduced 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.
Normal: write once; Special: write anytime EXCEPT the first time.
Read anytime.
MC68HC912DG128 — Rev 3.0
Technical Data
Bus Control and Input/Output
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