MC68HC08AZ16 Datasheet, PDF (332/527 Pages) Motorola, Inc – HCMOS Microcontroller Unit

I/O Ports
Port D
Port D
Port D is an 8-bit general-purpose I/O port.
Port D data register Port D is an 8 -bit special function port that shares seven of it’s pins with
(PTD)
the analog to digital converter and two with the TIMA and TIMB modules.
PTD
$0003
Read:
Write:
Reset:
ALTERNATE
FUNC TIONS
Bit 7
6
5
4
3
2
PTD7 PTD6 PTD5 PTD4 PTD3 PTD2
Unaffected by reset
R
ATD14/
TACLK
ATD13
ATD12/
TBCLK
ATD11
ATD10
Figure 10. Port D data register (PTD)
1
PTD1
ATD9
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.
Data direction register D determines whether each port D pin is an input
or an output. Writing a logic one to a DDRD bit enables the output buffer
for the corresponding port D pin; a logic zero disables the output buffer
ATD[14:8] — ADC channel status bits
PTD6/ATD14/TACLK-PTD0/ATD8 are seven of the 15 analog-to-digital
converter channels. The ATD 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 Appendix C: ADC-15
on page 487.)
NOTE: 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
MC68HC08AZ32
331