7470 datasheet(77/361 Pages) RENESAS

tên linh kiện	7470

Giải thích chi tiết về linh kiện	8-BIT SINGLE-CHIP MICROCOMPUTER 740 FAMILY / 7470 SERIES

PDF	361 Pages

Scroll/Zoom	100%

nhà sản xuất	RENESAS [Renesas Technology Corp]

Trang chủ	http://www.renesas.com

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77 / 361 page

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

1-70

HARDWARE

1.12 Timers

FF16

(n-1)16

to B

Timer 1 interrupt

enable bit

Count source

(CNTR0 pin)

Count period

T(s) = 1

÷ count source frequency ! (the timer initial value + 1)

Event counter mode operation example

• OF: Overflow

• RL: Reload

• n: Timer initial value

Timer 1 count stop bit

Down count

Timer 1 interrupt

request bit

“1” is written

“0” is written

Count stop

Count restart

A : • Clearing by writing “0” to the Timer 1 and CNTR interrupt request bits.

• Clearing by accepting the Timer 1 and CNTR interrupt requests when the timer 1 and

CNTR interrupt enable bits are “1.”

Time

CNTR interrupt

enable bit

CNTR interrupt

request bit

CNTR edge

selection bit

In this example, the CNTR interrupt request occurs at rising edge of the count source.

In this example, each CNTR interrupt request does not occur during executing the CNTR interrupt processing routine.

Fig. 1.12.4 Example of event counter mode operation

7470 bảng dữ liệu(PDF) 77 Page - Renesas Technology Corp