R8C datasheet(74/199 Pages) RENESAS

74 / 199 page

R8C/10 Group

Rev.1.20 Jan 27, 2006

page 64 of 180

REJ09B0019-0120

0F16

0E16

0E16 0D16 0C16 0B16 0A16 0916

0F16 0E16 0D16

0116 0016 0F16 0E16

0F16

0E16

0A16

0816

Timer X

reloads

0D16

0116

0F16 0E16

Timer X read

TXEDG bit in

TXMR register

(2)

Cleared to "0" by program

TXUND bit in

TXMR register

NOTES:

1. The contents of the read-out buffer can be read when the TX register is read in pulse period measurement mode.

2. After an active edge of measurement pulse is input, the TXEDG bit in the TXMR register is set to "1" (active edge found)

when the prescaler X underflows for the second time.

3. The TX register should be read before the next active edge is input after the TXEDG bit is set to "1" (active edge found).

The contents in the read-out buffer is retained until the TX register is read. If the TX register is not read before the next

active edge is input, the measured result of the previous period is retained.

4. When set to "0" by program, use a MOV instruction to write "0" to the TXEDG in the TXMR register. At the same time,

write "1" to the TXUND bit.

5. When set to "0" by program, use a MOV instruction to write "0" to the TXUND in the TXMR register. At the same time,

write "1" to the TXEDG bit.

6. The TXUND and TXEDG bits are both set to "1" if the timer underflows and reloads on an active edge simultaneously. In

this case, the validity of the TXUND bit should be determined by the contents of the read-out buffer.

7. If the CNTR0 active edge is input, when the prescaler X underflow signal is "H" level, its count value is the one of the

read buffer. If "L" level, the following count value is the one of the read buffer.

Conditions: A period from one rising edge to the next rising edge of measurement pulse is measured (R0EDG=0)

with TX register initial value=0F16.

Set to "1" by program

Starts counting

TXS bit in

TXMR register

“1”

“0”

“1”

“0”

CNTR0 pin

input

Timer X

contents

Contents of

read-out buffer1

Timer X

reloads

Timer X

reloads

Timer X read

(2)

(4)

(6)

Cleared to "0" by program

“1”

“0”

“1”

“0”

“1”

“0”

“1”

“0”

Cleared to “0” when interrupt request is accepted, or cleared by program

IR bit in INT1IC

IR bit in TXIC

0916

0016

Retained

0816

0F16

Underflow signal

of prescaler X

(3)

(7)

(5)

Figure 12.10 Operation Example in Pulse Period Measurement Mode

12.1 Timer (Timer X)

R8C датащи(PDF) 74 Page - Renesas Technology Corp

R8C датащи(HTML) 74 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

датащи скачать

ссылки URL