CLRC663 datasheet(13/177 Pages) NXP

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NXP Semiconductors

CLRC663

High performance multi-protocol NFC frontend CLRC663 and CLRC663 plus

The TControl register allows the global start and stop of each of the four timers Timer0 to Timer3. Additionally,

this register indicates if one of the timers is running or stopped. Each of the five timers implements an individual

configuration register set defining timer reload value (e.g. T0ReloadHi, T0ReloadLo), the timer value (e.g.

T0CounterValHi, T0CounterValLo) and the conditions which define start, stop and clockfrequency (e.g.

T0Control).

The external host may use these timers to manage timing relevant tasks. The timer unit may be used in one of

the following configurations:

• Time-out counter

• Watch-dog counter

• Stop watch

• Programmable one-shot timer

• Periodical trigger

The timer unit can be used to measure the time interval between two events or to indicate that a specific event

has occurred after an elapsed time. The timer register content is modified by the timer unit, which can be used

to generate an interrupt to allow a host to react on this event.

The counter value of the timer is available in the registers T(x)CounterValHi, T(x)CounterValLo. The content of

these registers is decremented at each timer clock.

If the counter value has reached a value of 0000h and the interrupts are enabled for this specific timer, an

interrupt will be generated as soon as the next clock is received.

If enabled, the timer event can be indicated on the pin IRQ (interrupt request). The bit Timer(x)IRQ can be set

and reset by the host controller. Depending on the configuration, the timer will stop counting at 0000h or restart

with the value loaded from registers T(x)ReloadHi, T(x)ReloadLo.

The counting of the timer is indicated by bit TControl.T(x)Running.

The timer can be started by setting bits TControl.T(x)Running and TControl.T(x)StartStopNow or stopped by

setting the bits TControl.T(x)StartStopNow and clearing TControl.T(x)Running.

Another possibility to start the timer is to set the bit T(x)Mode.T(x)Start. This can be useful if dedicated protocol

requirements need to be fulfilled.

CLRC663

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Product data sheet

Rev. 5.3 — 3 January 2024

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