mc9s12e256 Freescale Semiconductor, Inc, mc9s12e256 Datasheet - Page 527

• Manufacturer Part Number: mc9s12e256
• Description: Hcs12 Microcontrollers 16-bit Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

18.3.2.10 Pull Control Register (PUCR)
Read: Anytime (provided this register is in the map).
Write: Anytime (provided this register is in the map).
This register is used to select pull resistors for the pins associated with the core ports. Pull resistors are
assigned on a per-port basis and apply to any pin in the corresponding port that is currently configured as
an input. The polarity of these pull resistors is determined by chip integration. Please refer to
“MC9S12E256 Device Overview (MC9S12E256DGV1)”
This register is not in the on-chip memory map in expanded and special peripheral modes. Therefore, these
accesses will be echoed externally.
Freescale Semiconductor
PUPKE
PUPEE
PUPBE
PUPAE
Field
Reset
7
4
1
0
W
R
1
1. The default value of this parameter is shown. Please refer to
Pull resistors Port K Enable
0 Port K pull resistors are disabled.
1 Enable pull resistors for port K input pins.
Pull resistors Port E Enable
0 Port E pull resistors on bits 7, 4:0 are disabled.
1 Enable pull resistors for port E input pins bits 7, 4:0.
Note: Pins 5 and 6 of port E have pull resistors which are only enabled during reset. This bit has no effect on
Pull resistors Port B Enable
0 Port B pull resistors are disabled.
1 Enable pull resistors for all port B input pins.
Pull resistors Port A Enable
0 Port A pull resistors are disabled.
1 Enable pull resistors for all port A input pins.
(MC9S12E256DGV1)”
PUPKE
These bits have no effect when the associated pin(s) are outputs. (The pull
resistors are inactive.)
1
7
these pins.
= Unimplemented or Reserved
0
0
6
Figure 18-15. Pull Control Register (PUCR)
to determine the actual reset state of this register.
Table 18-9. PUCR Field Descriptions
MC9S12E256 Data Sheet, Rev. 1.08
0
0
5
PUPEE
NOTE
1
4
Description
to determine the polarity of these resistors.
Chapter 18 Multiplexed External Bus Interface (MEBIV3)
3
0
0
Chapter 1, “MC9S12E256 Device Overview
2
0
0
PUPBE
0
1
Chapter 1,
PUPAE
0
0
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