mc68hc908bd48 Freescale Semiconductor, Inc, mc68hc908bd48 Datasheet - Page 244

• Manufacturer Part Number: mc68hc908bd48
• Description: M68hc08 Microcontrollers Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

Input/Output (I/O) Ports
Data Sheet
244
PTDPUE Bit
Notes:
1. X = Don’t care
2. Hi-Z = High impedance
3. Writing affects data register, but does not affect input.
X
0
NOTE:
DDRD Bit
0
1
Avoid glitches on port D pins by writing to the port D data register before
changing data direction register D bits from 0 to 1.
Figure 17-14
When bit DDRDx is a logic 1, reading address $0003 reads the PTDx
data latch. When bit DDRDx is a logic 0, reading address $0003 reads
the voltage level on the pin. The data latch can always be written,
regardless of the state of its data direction bit.
the operation of the port D pins.
PTD Bit
X
X
Table 17-6. Port D Pin Functions
READ DDRD ($0007)
WRITE DDRD ($0007)
WRITE PTD ($0003)
READ PTD ($0003)
I/O Pin Mode
Input, Hi-Z
Output
shows the port D I/O logic.
Input/Output (I/O) Ports
Figure 17-14. Port D I/O Circuit
RESET
(2)
Accesses to DDRD
DDRD6–DDRD0
DDRD6–DDRD0
Read/Write
DDRDx
PTDx
PTD6–PTD0
Table 17-6
MC68HC908BD48
Read
Pin
Accesses to PTD
Freescale Semiconductor
PTD6–PTD0
summarizes
PTD6–PTD0
Write
—
Rev. 2.1
PTDx
(3)