MC68HC908AZ60 Datasheet, PDF (317/480 Pages) Motorola, Inc – HCMOS Microcontroller Unit

Port D
Port D Data
Register
I/O Ports
Port D
Port D is an 8-bit general-purpose I/O port.
Port D is a 8-bit special function port that shares seven of its pins with
the analog to digital converter and two with the timer interface
modules.
Address: $0003
Bit 7
6
5
4
3
2
1
Read:
PTD7
Write:
PTD6
PTD5
PTD4
PTD3
PTD2
PTD1
Reset:
Unaffected by Reset
Alternate
Functions:
R
ATD14/
TACLK
ATD13
ATD12/
TBCLK
ATD11
ATD10
ATD9
Figure 11. Port D Data Register (PTD)
Bit 0
PTD0
ATD8
PTD[7:0] — Port D Data Bits
PTD[7:0] are read/write, software programmable bits. Data direction
of PTD[7:0] pins are under the control of the corresponding bit in data
direction register D.
ATD[14:8] — ADC Channel Status Bits
PTD6/ATD14/TACLK–PTD0/ATD8 are seven of the 15 analog-to-
digital converter channels. The ADC channel select bits, CH[4:0],
determine whether the PTD6/ATD14/TACLK–PTD0/ATD8 pins are
ADC channels or general-purpose I/O pins. If an ADC channel is
selected and a read of this corresponding bit in the port B data register
occurs, the data will be 0 if the data direction for this bit is
programmed as an input. Otherwise, the data will reflect the value in
the data latch. (See Analog-to-Digital Converter (ADC-15) on page 421).
Data direction register D (DDRD) does not affect the data direction of
port D pins that are being used by the TIMA or TIMB. However, the
11-io
MOTOROLA
I/O Ports
MC68HC908AZ60 — Rev 2.0
315