MPC89x53AF datasheet(17/38 Pages) MEGAWIN

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Timer2 is also can be configured as a periodical signal generator.

The MPC89x53A is able to generate a programmable clock output on P1.0. When T2OE bit is

set and C//T2 bit is cleared, Timer2 overflow pulse will generate a 50% duty clock and output

that to P1.0. The frequency of clock-out is calculated according to the following formula.

Oscillator frequency

4 x (65536 – RCAP2H, RCAP2L)

In the clock-out mode, Timer2 rollovers will not generate an interrupt.

Capture Mode (CP)

In the Capture mode, Timer2 is incremented by either OSC/12 or external pin (T2) 1-to-0

transition. TR2 controls the event to timer2 and a 1-to-0 transition on T2EX pin will trigger

RCAP2H and RCAP2L registers to capture the Timer2 contents onto them if EXEN2 is set. An

overflow in Timer2 sets TF2 flag and a 1-to-0 transition in T2EX pin sets EXF2 flag if EXEN2=1.

TF2 and EXF2 is ORed to request the interrupt service.

OSC/12

T2 pin

TR2

TL2 [7:0]

TF2

Interrupt

C//T2

TH2[7:0]

RCAP2L [7:0]

RCAP2H [7:0]

T2EX pin

EXEN2

EXF2

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MPC89x53A Data Sheet

MPC89x53AF Datasheet(PDF) 17 Page - Megawin Technology Co., Ltd