mc68hc908ld64 Freescale Semiconductor, Inc, mc68hc908ld64 Datasheet - Page 312

• Manufacturer Part Number: mc68hc908ld64
• Description: M68hc08 Microcontrollers Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

Input/Output (I/O) Ports
19.7.2 Data Direction Register E
Data Sheet
312
NOTE:
Address:
Data direction register E (DDRE) 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[7:0] — 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 19-19
Reset:
Read:
Write:
These read/write bits control port E data direction. Reset clears
DDRE[7:0], configuring all port E pins as inputs.
1 = Corresponding port E pin configured as output
0 = Corresponding port E pin configured as input
DDRE7
READ DDRE ($0009)
WRITE DDRE ($0009)
WRITE PTE ($0008)
READ PTE ($0008)
$0009
Bit 7
Figure 19-18. Data Direction Register E (DDRE)
0
shows the port E I/O logic.
Input/Output (I/O) Ports
DDRE6
6
0
Figure 19-19. Port E I/O Circuit
RESET
DDRE5
5
0
DDRE4
DDREx
PTEx
4
0
DDRE3
3
0
MC68HC908LD64
DDRE2
Freescale Semiconductor
2
0
DDRE1
1
0
—
Rev. 3.0
DDRE0
Bit 0
0
PTEx