mc68hc908jb16 Freescale Semiconductor, Inc, mc68hc908jb16 Datasheet - Page 277

• Manufacturer Part Number: mc68hc908jb16
• Description: M68hc08 Microcontrollers Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

14.6.2 Data Direction Register E
MC68HC908JB16
Freescale Semiconductor
NOTE:
NOTE:
—
Rev. 1.1
Address:
Data direction register E (DDRE) does not affect the data direction of
port E pins that are being used by the TIM. However, the DDRE bits
always determine whether reading port E returns the states of the
latches or the states of the pins.
Data direction register E determines whether each port E pin is an input
or an output. Writing a logic 1 to a DDRE bit enables the output buffer for
the corresponding port E pin; a logic 0 disables the output buffer.
DDRE[4:0] — Data Direction Register E Bits
Avoid glitches on port E pins by writing to the port E data register before
changing data direction register E bits from 0 to 1.
Figure 14-13
Reset:
Read:
Write:
These read/write bits control port E data direction. Reset clears
DDRE[4:0], configuring all port E pins as inputs.
1 = Corresponding port E pin configured as output
0 = Corresponding port E pin configured as input
$0009
Bit 7
Figure 14-12. Data Direction Register E (DDRE)
0
0
shows the port E I/O circuit logic.
Input/Output (I/O) Ports
= Unimplemented
6
0
0
5
0
0
DDRE4
4
0
DDRE3
3
0
DDRE2
2
0
Input/Output (I/O) Ports
DDRE1
1
0
Technical Data
DDRE0
Bit 0
0
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