7733 datasheet(173/940 Pages) RENESAS

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TIMER B

7733 Group User’s Manual

7–10

7.3 Timer mode (Bits 1 and 0 of timer Bi mode register = “002”)

In this mode, a count source internally generated is counted. (Refer to Table 7.3.1.) Figure 7.3.1 shows the

structures of the timer Bi mode register and timer Bi register in the timer mode.

Table 7.3.1 Specifications of timer mode

Item

Count source

Count operation

Division ratio

Count start condition

Count stop condition

Interrupt request occurrence timing

Pin TBiIN’s function

Read from timer

Write to timer

Specifications

Clock f2, f16, f64, or f512

q Countdown

q At an underflow, the reload register’s contents is reloaded, and counting

is continued.

n: Set value in the timer Bi register

When the count start flag is set to “1.”

When the count start flag is cleared to “0.”

At an underflow

Programmable I/O port (Pin TB2IN is a programmable I/O port or

φSUB output pin.)

A counter value can be read out by reading the timer Bi register.

s While counting is stopped

When a value is written to the timer Bi register, it is written to both

of the reload register and counter.

s While counting is in progress

When a value is written to the timer Bi register, it is written only to

the reload register. (Transferred to the counter at the next reload

time.)

(n + 1)

Clocks f2, f16, f64, and f512: Refer to chapter “14. CLOCK GENERATING CIRCUIT.”

7.3 Timer mode

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