MC908GR8CDWE Datasheet, PDF (223/408 Pages) Freescale Semiconductor, Inc – M68HC08 Microcontrollers

Freescale Semiconductor, Inc.
Input/Output Ports (I/O)
Port D
READ DDRD ($0007)
WRITE DDRD ($0007)
RESET
WRITE PTD ($0003)
VDD
DDRDx
PTDx
PTDPUEx
READ PTD ($0003)
INTERNAL
PULLUP
DEVICE
PTDx
Figure 16-15. Port D I/O Circuit
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. Table 16-5 summarizes
the operation of the port D pins.
Table 16-5. Port D Pin Functions
Accesses to DDRD
PTDPUE Bit DDRD Bit PTD Bit I/O Pin Mode
Read/Write
Accesses to PTD
Read
Write
1
0
X⁽¹⁾
Input, V_DD(4)
DDRD6–DDRD0
Pin
PTD6–PTD0⁽³⁾
0
0
X
Input, Hi-Z^{(2) DDRD6–DDRD0}
Pin
PTD6–PTD0⁽³⁾
X
1
X
Output
DDRD6–DDRD0 PTD6–PTD0 PTD6–PTD0
Notes:
1. X = Don’t care
2. Hi-Z = High impedance
3. Writing affects data register, but does not affect input.
4. I/O pin pulled up to V_DD by internal pullup device.
MC68HC908GR8 — Rev 4.0
MOTOROLA
Input/Output Ports (I/O)
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Technical Data
223