W77E058A Datasheet, PDF (59/87 Pages) Winbond – 8-BIT MICROCONTROLLER

W77E058A
12.3.5 Programmable Clock-out
Timer 2 is equipped with a new clock-out feature which outputs a 50% duty cycle clock on P1.0. It can
be invoked as a programmable clock generator. To configure Timer 2 with clock-out mode, software
must initiate it by setting bit T2OE = 1, C/T2 = 0 and CP/RL = 0. Setting bit TR2 will start the timer.
This mode is similar to the baud rate generator mode, it will not generate an interrupt while Timer 2
overflow. So it is possible to use Timer 2 as a baud rate generator and a clock generator at the same
time. The clock-out frequency is determined by the following equation:
The Clock-Out Frequency = Oscillator Frequency / [4 X (RCAP2H, RCAP2L) ]
Clock Source
Mode input
div. by 4 osc/2
div. by 64 osc/32
div. by 1024 osc/512
TR2 = T2CON.2
T2EX = P1.1
EXEN2 = T2CON.3
TL2 TH2
1/2
T2=P1.0
RCAP2L RCAP2H
EXF2
T2CON.6
Timer 2
Interrupt
Figure 18. Programmable Clock-Out Mode
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Publication Release Date: April 17, 2007
Revision A10