83C166 Siemens Semiconductor Group, 83C166 Datasheet - Page 19

• Manufacturer Part Number: 83C166
• Description: 16-Bit CMOS Single-Chip Microcontroller
• Manufacturer: Siemens Semiconductor Group

SAB 80C166/83C166
The count direction (up/down) for each timer is programmable by software. For timer T3 the count
direction may additionally be altered dynamically by an external signal on a port pin (T3EUD) to
facilitate e. g. position tracking.
Timer T3 has an output toggle latch (T3OTL) which changes its state on each timer over-flow/
underflow. The state of this latch may be output on a port pin (T3OUT) e. g. for timeout monitoring
of external hardware components, or may be used internally to clock timers T2 and T4 for
measuring long time periods with high resolution.
In addition to their basic operating modes, timers T2 and T4 may be configured as reload or capture
registers for timer T3. When used as capture or reload registers, timers T2 and T4 are stopped. The
contents of timer T3 is captured into T2 or T4 in response to a signal at their associated input pins
(TxIN). Timer T3 is reloaded with the contents of T2 or T4 triggered either by an external signal or
by a selectable state transition of its toggle latch T3OTL. When both T2 and T4 are configured to
alternately reload T3 on opposite state transitions of T3OTL with the low and high times of a PWM
signal, this signal can be constantly generated without software intervention.
Figure 7
Block Diagram of GPT2
Semiconductor Group
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