7906 datasheet(114/531 Pages) RENESAS

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TIMER A

7906 Group User’s Manual Rev.2.0

7-11

7.3 Timer mode

In this mode, the timer counts an internally generated count source. Table 7.3.1 lists the specifications of

the timer mode. Figure 7.3.1 shows the structures of the timer Ai register and timer Ai mode register in the

timer mode.

Table 7.3.1 Specifications of timer mode

Item

Count source fi

Count operation

Division ratio

Count start condition

Count stop condition

Interrupt request occurrence timing

TAjIN pin function

TAjOUT pin function

Read from timer Ai register

Write to timer Ai register

Specifications

f1, f2, f16, f64, f512, or f4096

• Countdown

• When a counter underflow occurs, reload register’s contents are

reloaded, and counting continues.

When count start bit is set to “1.”

When count start bit is cleared to “0.”

When a counter underflow occurs.

Programmable I/O port pin or gate input pin

Programmable I/O port pin or pulse output pin

Counter value can be read out.

q While counting is stopped

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

reload register and counter.

q While counting is in progress

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

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

n : Timer Ai register setting value

(n + 1)

7.3 Timer mode

Note: Only timer Aj (j = 0 to 2, 4, 9) is equipped with the I/O pins.

7906 Datasheet(PDF) 114 Page - Renesas Technology Corp