mc68hc912bc32 Freescale Semiconductor, Inc, mc68hc912bc32 Datasheet - Page 91

• Manufacturer Part Number: mc68hc912bc32
• Description: M68hc12 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

6.3.8 Pullup Control Register
Read: Anytime, if register is in the map
Write: Anytime, if register is in the map
These bits select pullup resistors for any pin in the corresponding port that is currently configured as an
input. This register is not in the map in peripheral mode.
PUPE — Pullup Port E Enable Bit
PUPB — Pullup Port B Enable Bit
PUPA — Pullup Port A Enable Bit
Freescale Semiconductor
Pin PE1 always has a pullup. Pins PE6, PE5, and PE4 never have pullups.
This bit has no effect if port B is used as part of the address/data bus (pullups are inactive).
This bit has no effect, if port A is used as part of the address/data bus (pullups are inactive).
1 = Enable port E pullups on PE7, PE3, PE2, PE1, and PE0
0 = Disable port E pullups on PE7, PE3, PE2, PE1, and PE0
1 = Enable pullups for all port B input pins
0 = Disable port B pullups
0 = Disable port A pullups
1 = Enable pullups for all port A input pins
Address: $000C
Reset:
Read:
Write:
Bit 7
0
0
Figure 6-8. Pullup Control Register (PUCR)
= Unimplemented
6
0
0
M68HC12B Family Data Sheet, Rev. 9.1
5
0
0
PUPE
4
1
3
0
0
2
0
0
PUPB
1
0
PUPA
Bit 0
0
Registers
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