MC68HC812A4 Datasheet, PDF (108/342 Pages) Motorola, Inc – 16-bit device composed of standard on-chip peripheral modules connected by an intermodule bus. Modules include

Bus Control and Input/Output (I/O)
PUPC — Pullup Port C Enable Bit
1 = Enable pullup devices for all port C input pins
0 = Port C pullups disabled
This bit has no effect if port C is being used as part of the data bus
(the pullups are inactive).
PUPB — Pullup Port B Enable Bit
1 = Enable pullup devices for all port B input pins
0 = Port B pullups disabled
This bit has no effect if port B is being used as part of the address bus
(the pullups are inactive).
PUPA — Pullup Port A Enable Bit
1 = Enable pullup devices for all port A input pins
0 = Port A pullups disabled
This bit has no effect if port A is being used as part of the address bus
(the pullups are inactive).
6.4.13 Reduced Drive Register
Address: $000D
Bit 7
6
5
4
3
2
1
Bit 0
Read:
RDPJ
Write:
RDPH
RDPG
RDPF
RDPE
PRPD
RDPC RDPAB
Reset: 0
0
0
0
0
0
0
0
Figure 6-13. Reduced Drive Register (RDRIV)
Read: Anytime, if register is in the map
Write: Anytime, in normal modes; never in special modes
This register is not in the map in peripheral mode.
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.
MC68HC812A4 — Rev. 3.0
108
Bus Control and Input/Output (I/O)
Advance Information
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