4584 datasheet(39/157 Pages) RENESAS

39 / 157 page

Rev.3.00

2004.08.06

page 39 of 155

REJ03B0010-0300Z

4584 Group

PRELIMINARY

Notice: This is not a final specification.

Some parametric limits are subject to change.

; (✕0✕✕2)

TV1A

; The SNZT1 instruction is valid ........ ➀

; (✕0✕✕2)

TW5A

; Period measurement circuit stop

NOP

........................................................... ➁

SNZT1

; The SNZT1 instruction is executed

(T1F flag cleared)

NOP

........................................................... ➂

✕ : these bits are not used here.

Fig. 27 Period measurement circuit program example

(7) Period measurement function (Timer 1,

period measurement circuit)

Timer 1 has the period measurement circuit which performs timer

count operation synchronizing with the one cycle of the signal di-

vided by 16 of an on-chip oscillator, D6/CNTR0 pin input, or P30/

INT0 pin input (one cycle, “H”, or “L” pulse width at the case of a

P30/INT0 pin input).

When the target signal for period measurement is set by bits 0

and 1 of register W5, a period measurement circuit is started by

setting the bit 2 of register W5 to “1”.

Then, if a XIN input is set as the count source of a timer 1 and the

bit 2 of register W1 is set to “1”, timer 1 starts operation.

Timer 1 starts operation synchronizing with the falling edge of the

target signal for period measurement, and stops count operation

synchronizing with the next falling edge (one-period generation

circuit).

When selecting D6/CNTR0 pin input as target signal for period

measurement, the period measurement synchronous edge can

be changed into a rising edge by setting the bit 2 of register W6

to “1”.

When selecting P30/INT0 pin input as target signal for period

measurement, period measurement synchronous edge can be

changed into a rising edge by setting the bit 2 of register I1 to “1”.

A timer 1 interrupt request flag (T1F) is set to “1” after completing

measurement operation.

When a period measurement circuit is set to be operating, timer

1 interrupt request flag (T1F) is not set by timer 1 underflow sig-

nal, but turns into a flag which detects the completion of period

measurement.

In addition, a timer 1 underflow signal can be used as timer 2

count source.

Once period measurement operation is completed, even if period

measurement valid edge is input next, timer 1 is in a stop state

and measurement data is held.

When a period measurement circuit is used again, stop a period

measurement circuit at once by setting the bit 2 of register W5 to

“0”, and change a period measurement circuit into a state of op-

eration by setting the bit 2 of register W5 to “1” again.

When a period measurement circuit is used, clear bit 0 of regis-

ter I1 to “0”, and set a timer 1 count start synchronous circuit to

be “not selected”.

Start timer operation immediately after operation of a period

measurement circuit is started.

When the target edge for measurement is input until timer opera-

tion is started from the operation of period measurement circuit is

started, the count operation is not executed until the timer opera-

tion becomes valid. Accordingly, be careful of count data.

When data is read from timer, stop the timer and clear bit 2 of

then execute the data read instruction.

Depending on the state of timer 1, the timer 1 interrupt request

flag (T1F) may be set to “1” when the period measurement cir-

cuit is stopped by clearing bit 2 of register W5 to “0”. In order to

avoid the occurrence of an unexpected interrupt, clear the bit 2 of

In addition, execute the SNZT1 instruction to clear the T1F flag

after executing at least one instruction (refer to Figure 27➁).

Also, set the NOP instruction for the case when a skip is per-

formed with the SNZT1 instruction (refer to Figure 27➂).

When a period measurement circuit is used, select the suffi-

ciently higher-speed frequency than the signal for measurement

for the count source of a timer 1.

When the target signal for period measurement is D6/CNTR0 pin

input, do not select D6/CNTR0 pin input as timer 1 count source.

(The XIN input is recommended as timer 1 count source at the

time of period measurement circuit use.)

(8) Pulse width measurement function (timer

1, period measurement circuit)

A period measurement circuit can measure “H” pulse width (from

rising to falling) or “L” pulse width (from falling to rising) of P30/

INT0 pin input (pulse width measurement function) when the fol-

lowing is set;

• Set the bit 0 of register W5 to “0”, and set a bit 1 to “1” (target

for period measurement circuit: 30/INT0 pin input).

• Set the bit 1 of register I1 to “1” (INT0 pin edge detection circuit:

both edges detection)

The measurement pulse width (“H” or “L”) is decided by the pe-

riod measurement circuit and the P30/INT0 pin input level at the

start time of timer operation.

At the time of the start of a period measurement circuit and timer

operation, “L” pulse width (from falling to rising) when the input

level of P30/INT0 pin is “H” or “H” pulse width (from rising to fall-

ing) when its level is “L” is measured.

When the input of P30/INT0 pin is selected as the target for mea-

surement, set the bit 3 of register I1 to “1”, and set the input of

INT0 pin to be enabled.

4584 数据表(PDF) 39 Page - Renesas Technology Corp

4584 数据表(HTML) 39 Page - Renesas Technology Corp

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

数据表下载