SAB80C166W Datasheet, PDF (17/67 Pages) Siemens Semiconductor Group – C16x-Family of High-Performance CMOS 16-Bit Microcontrollers

SAB 80C166W/83C166W
General Purpose Timer (GPT) Unit
The GPT unit represents a very flexible multifunctional timer/counter structure which may be used
for many different time related tasks such as event timing and counting, pulse width and duty cycle
measurements, pulse generation, or pulse multiplication.
The GPT unit incorporates five 16-bit timers which are organized in two separate modules, GPT1
and GPT2. Each timer in each module may operate independently in a number of different modes,
or may be concatenated with another timer of the same module.
Each of the three timers T2, T3, T4 of module GPT1 can be configured individually for one of three
basic modes of operation, which are Timer, Gated Timer, and Counter Mode. In Timer Mode, the
input clock for a timer is derived from the CPU clock, divided by a programmable prescaler, while
Counter Mode allows a timer to be clocked in reference to external events.
Pulse width or duty cycle measurement is supported in Gated Timer Mode, where the operation of
a timer is controlled by the ‘gate’ level on an external input pin. For these purposes, each timer has
one associated port pin (TxIN) which serves as gate or clock input. The maximum resolution of the
timers in module GPT1 is 400 ns (@ 20 MHz CPU clock).
Figure 6
Block Diagram of GPT1
Semiconductor Group
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