7721 datasheet(130/577 Pages) RENESAS

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TIMER A

7721 Group User’s Manual

8–11

8.3 Timer mode

8.3.1 Setting for timer mode

Figures 8.3.2 and 8.3.3 show an initial setting example for registers relevant to the timer mode.

Note that when using interrupts, set up to enable the interrupts. For details, refer to section “CHAPTER

7. INTERRUPTS.”

Fig. 8.3.2 Initial setting example for registers relevant to timer mode (1)

Note: The counter divides the count source frequency by (n + 1).

Setting division ratio

Can be set to “000016” to “FFFF16” (n).

(b15)

(b8)

Timer A0 register (Addresses 4716, 4616)

Timer A1 register (Addresses 4916, 4816)

Timer A2 register (Addresses 4B16, 4A16)

Timer A3 register (Addresses 4D16, 4C16)

Timer A4 register (Addresses 4F16, 4E16)

Continue to Figure 8.3.3 on next page.

Pulse output function select bit

0: No pulse output.

1: Pulses output.

Selecting timer mode and each function

Timer Ai mode register (i = 0 to 4) (Addresses 5616 to 5A16)

Count source select bits

0 0: f2

0 1: f16

1 0: f64

1 1: f512

b7 b6

Gate function select bits

0 0:

0 1:

1 0: Gate function (Counter counts only while TAjIN pin’s input signal is at “L” level.)

1 1: Gate function (Counter counts only while TAjIN pin’s input signal is at “H” level.)

b4 b3

Selection of timer mode

No gate function

Note: For Timers A0 and A1, set bits 0 to 5 to “0.”

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