MC68HC812A4 Datasheet, PDF (206/342 Pages) Motorola, Inc – 16-bit device composed of standard on-chip peripheral modules connected by an intermodule bus. Modules include

Standard Timer Module
12.11.1 Timer Port Data Register
An I/O pin used by the timer defaults to general-purpose I/O unless an
internal function which uses that pin is enabled.
Address: $00AE
Bit 7
6
5
4
3
2
1
Read:
PT7
PT6
PT5
PT4
PT3
PT2
PT1
Write:
Reset:
Unaffected by reset
Timer function: IC/OC7 IC/OC6 IC/OC5 IC4OC4 IC/OC3 IC/OC2 IC/OC1
PA function: PAI
Figure 12-25. Timer Port Data Register (PORTT)
Read: Anytime
Write: Anytime
Bit 0
PT0
IC/OC0
PT7–PT0 — Timer Port Data Bits
Data written to PORTT is buffered and drives the pins only when they
are configured as general-purpose outputs.
Reading an input (data direction bit = 0) reads the pin state; reading
an output (data direction bit = 1) reads the latch.
Writing to a pin configured as a timer output does not change the pin
state.
NOTE:
Due to input synchronizer circuitry, the minimum pulse width for a pulse
accumulator input or an input capture input should always be greater
than the width of two module clocks.
Table 12-6. TIMPORT I/O Function
In
Data Direction Output Compare
Register
Action
0
0
0
1
1
1
1
0
Out
Reading
at Data Bus
Reading at Pin
Pin
Pin
Pin
Output compare action
Port data register Output compare action
Port data register Port data register
MC68HC812A4 — Rev. 3.0
206
Standard Timer Module
Advance Information
MOTOROLA