7477 datasheet(93/354 Pages) RENESAS

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

1-76

HARDWARE

1.12 Timers

[Setting method]

1 The count operation of Timer 4 is stopped by setting bit 3 of the Timer 34 mode register to “1.”

Refer to “Table 1.12.2 Setting for count stop.”

2 Set each register according to the external pulse width measuring mode setting shown in Table

1.12.12.

3 Set a value in the timer.

Refer to “Table 1.12.7 Address allocation of timer.”

4 Clear bit 3 of the Timer 34 mode register to "0" and start the count of timer 4.

Refer to “Table 1.12.8 Count start setting.”

Table 1.12.12 External pulse width measurement mode setting

Notes 1:

0: The count source is counted while the external pulse is “H.”

1: The count source is counted while the external pulse is “L.”

When the measured pulse is the CNTR1 pin, do not select the CNTR1 as the count source of

Timer 4.

–

Select

(Note 1)

Timer 34 mode register

(T34M: Address 00F816)

Edge polarity selection register

(EG: Address 00D416)

Timer to

be used

Timer 4

Measuring

pulse

CNTR0

CNTR1

b5 b4

0 : Timer 3 overflow signal

1 : f (XIN)/16 or f (XCIN)/16

10 : Timer 1 or Timer 2 overflow signal

1 : CNTR1 pin (Note 2)

Select

(Note 1)

–

7477 Datasheet(PDF) 93 Page - Renesas Technology Corp