Datasheet

Registers
MC68HC812A4 Data Sheet, Rev. 7
Freescale Semiconductor 71
6.3.12 Pullup Control Register
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).
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).
Address: $000C
Bit 7654321Bit 0
Read:
PUPH PUPG PUPF PUPE PUPD PUC PUPB PUPA
Write:
Reset:11111111
Figure 6-12. Pullup Control Register (PUCR)