7477 datasheet(92/354 Pages) RENESAS

Part #	7477

Description	8-BIT SINGLE-CHIP MICROCOMPUTER 740 FAMILY / 7470 SERIES

PDF	354 Pages

Scroll/Zoom	100%

Manufacturer	RENESAS [Renesas Technology Corp]

Direct Link	http://www.renesas.com

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92 / 354 page

1-75

7470/7471/7477/7478 GROUP USER’S MANUAL

HARDWARE

1.12 Timers

Fig. 1.12.6 Example of operation of external pulse width measurement mode

Timer 4 count

source

Pulse width

H(s) = 1

÷ count source frequency ! (the timer initial value - count value at count stop)

External pulse width measurement mode operation example

• n: Timer initial value

• m: Count value at count stop

Timer 4 count stop bit

CNTR0 pin

m16

FF16

(n-1)16

Timer 4 interrupt

enable bit

Timer 4 interrupt

request bit

Count start

A : • Clearing by writing “0” to the CNTR interrupt request bit.

• Clearing by accepting the CNTR interrupt request when the CNTR interrupt enable bit is “1.”

V : When the CNTR edge selection bit is “0,” “H” level width of the input pulse is measured.

CNTR

edge selection bit

Count start

Count stop

Time

CNTR interrupt

enable bit

CNTR interrupt

request bit

Setting the initial value

to timer

Setting the initial value

to timer

7477 Datasheet(PDF) 92 Page - Renesas Technology Corp