XC908AS60ACFU Motorola Semiconductor Products, XC908AS60ACFU Datasheet - Page 377

• Manufacturer Part Number: XC908AS60ACFU
• Description: MC68HC908AZ60A, MC68HC908AS60A Hcmos Microcontroller Unit Technical Data
• Manufacturer: Motorola Semiconductor Products

22.10.2 Data Direction Register H
MC68HC908AZ60A — Rev 2.0
MOTOROLA
NOTE:
Address:
Data direction register H determines whether each port H pin is an input
or an output. Writing a logic 1 to a DDRH bit enables the output buffer for
the corresponding port H pin; a logic 0 disables the output buffer.
DDRH[1:0] — Data Direction Register H Bits
Avoid glitches on port H pins by writing to the port H data register before
changing data direction register H bits from 0 to 1.
Figure 22-25
Reset:
Read:
Write:
These read/write bits control port H data direction. Reset clears
DDRG[1:0], configuring all port H pins as inputs.
1 = Corresponding port H pin configured as output
0 = Corresponding port H pin configured as input
READ DDRH ($000F)
WRITE DDRH ($000F)
WRITE PTH ($000B)
READ PTH ($000B)
$000F
Bit 7
Figure 22-24. Data Direction Register H (DDRH)
R
R
0
0
shows the port H I/O logic.
= Reserved
Input/Output Ports
R
6
0
0
Figure 22-25. Port H I/O Circuit
RESET
R
5
0
0
DDRHx
R
PTHx
4
0
0
R
3
0
0
R
2
0
0
Input/Output Ports
DDRH1
1
0
Technical Data
DDRH0
Bit 0
Port H
0
PTHx
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