Datasheet

Pinout and Signal Descriptions
Technical Data MC68HC912DT128A — Rev 4.0
65 Pinout and Signal Descriptions MOTOROLA
3.5.16 Port Pull-Up Pull-Down and Reduced Drive
MCU ports can be configured for internal pull-up. To reduce power
consumption and RFI, the pin output drivers can be configured to
operate at a reduced drive level. Reduced drive causes a slight increase
in transition time depending on loading and should be used only for ports
which have a light loading. Table 3-4 summarizes the port pull-up default
status and controls.
Port S
PS[7:0]
96–89
In/Out
DDRS ($00D7)
Serial communications interfaces 1 and 0 and serial peripheral
interface subsystems; or general-purpose I/O.
Port T
PT[7:0]
18–15,
7–4
In/Out
DDRT ($00AF)
General-purpose I/O when not enabled for input capture and
output compare in the timer and pulse accumulator
subsystem.
1. MC68HC912DT128A only
2. MC68HC912DG128A only
Table 3-3. MC68HC912DT128A Port Description Summary
Port Name
Pin
Numbers
Data Direction
Register (Address)
Description
112-pin
Table 3-4. Port Pull-Up, Pull-Down and Reduced Drive Summary
Enable Bit Reduced Drive Control Bit
Port
Name
Resistive
Input Loads
Register
(Address)
Bit Name
Reset
State
Register
(Address)
Bit Name
Reset
State
Port A Pull-up PUCR ($000C) PUPA Disabled RDRIV ($000D) RDPA Full drive
Port B Pull-up PUCR ($000C) PUPB Disabled RDRIV ($000D) RDPB Full drive
Port E:
PE7, PE[3:2] Pull-up PUCR ($000C) PUPE Enabled RDRIV ($000D) RDPE Full drive
PE[1:0] Pull-up PUCR ($000C) PUPE Enabled —
PE[6:4] None — RDRIV ($000D) RDPE Full drive
Port H
Pull-up or
Pull-down
PUCR ($000C) PUPH Disabled RDRIV ($000D) RDPH Full drive
Port J
Pull-up or
Pull-down
PUCR ($000C) PUPJ Disabled RDRIV ($000D) RDPJ Full drive
Port K Pull-up PUCR ($000C) PUPK Disabled RDRIV ($000D) RDPK Full drive
Port P Pull-up PWCTL ($0054) PUPP Disabled PWCTL ($0054) RDPP Full drive
Port S Pull-up SP0CR2 ($00D1) PUPS Enabled SP0CR2 ($00D1) RDPS Full drive
Port T Pull-up TMSK2 ($008D) TPU Disabled TMSK2 ($008D) TDRB Full drive
Port IB[7:6] Pull-up IBPURD ($00E5) PUPIB Disabled IBPURD ($00E5) RDPIB Full drive
Frees
cale Semiconductor,
I
Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
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