MC68HC812A4 Datasheet, PDF (107/342 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)
Registers
6.4.12 Pullup Control Register
Address: $000C
Bit 7
6
5
4
3
2
1
Read:
PUPH PUPG PUPF PUPE PUPD PUC PUPB
Write:
Reset: 1
1
1
1
1
1
1
Figure 6-12. Pullup Control Register (PUCR)
Bit 0
PUPA
1
Read: Anytime, if register is in the map
Write: Anytime, if register is in the map
This register is not in the map in peripheral mode.
These bits select pullup resistors for any pin in the corresponding port
that is currently configured as an input.
PUPH — Pullup Port H Enable Bit
1 = Enable pullup devices for all port H input pins
0 = Port H pullups disabled
PUPG — Pullup Port G Enable Bit
1 = Enable pullup devices for all port G input pins
0 = Port G pullups disabled
PUPF — Pullup Port F Enable Bit
1 = Enable pullup devices for all port F input pins
0 = Port F pullups disabled
PUPE — Pullup Port E Enable Bit
1 = Enable pullup devices for port E input pins PE3, PE2, and PE0
0 = Port E pullups on PE3, PE2, and PE0 disabled
PUPD — Pullup Port D Enable Bit
1 = Enable pullup devices for all port D input pins
0 = Port D pullups disabled
This bit has no effect if port D is being used as part of the data bus
(the pullups are inactive).
Advance Information
MOTOROLA
Bus Control and Input/Output (I/O)
MC68HC812A4 — Rev. 3.0
107