7721 datasheet(177/577 Pages) RENESAS

177 / 577 page

7721 Group User’s Manual

TIMER B

9–10

9.3 Timer mode

9.3.1 Setting for timer mode

Figure 9.3.2 shows 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 “CHAPTER 7.

INTERRUPTS.”

Fig. 9.3.2 Initial setting example for registers relevant to timer mode

Count Starts

Count source select bits

0 0 : f2

0 1 : f16

1 0 : f64

1 1 : f512

Selecting timer mode and count source

Timer Bi mode register (i = 0 to 2)

(Addresses 5B16 to 5D16)

Setting count start bit to “1”

Count start register (Address 4016)

Timer B0 count start bit

Timer B1 count start bit

Timer B2 count start bit

b7 b6

Setting interrupt priority level

Timer Bi interrupt control register (i = 0 to 2)

(Addresses 7A16 to 7C16)

Interrupt priority level select bits

When using interrupts, set these bits to one of levels 1 to 7.

When disabling interrupts, set these bits to level 0.

!: It may be either “0” or “1.”

Selection of timer mode

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

Setting division ratio

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

(b15)

(b8)

Timer B0 register (Addresses 5116, 5016)

Timer B1 register (Addresses 5316, 5216)

Timer B2 register (Addresses 5516, 5416)

7721 Datasheet(PDF) 177 Page - Renesas Technology Corp