C161O datasheet(21/66 Pages) INFINEON

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C161K

C161O

Data Sheet

V2.0, 2001-01

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 four basic modes of operation, which are Timer, Gated Timer, Counter, and

Incremental Interface 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 16 TCL.

The count direction (up/down) for each timer is programmable by software or may

additionally be altered dynamically by an external signal on a port pin (TxEUD) to

facilitate e.g. position tracking.

In Incremental Interface Mode the GPT1 timers (T2, T3, T4) can be directly connected

to the incremental position sensor signals A and B via their respective inputs TxIN and

TxEUD. Direction and count signals are internally derived from these two input signals,

so the contents of the respective timer Tx corresponds to the sensor position. The third

position sensor signal TOP0 can be connected to an interrupt input.

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 pin T3OUT e.g. for time out

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.

C161O Datasheet(PDF) 21 Page - Infineon Technologies AG