M16CSLASH62P datasheet(97/349 Pages) MITSUBISHI

97 / 349 page

Watchdog Timer

Mitsubishi microcomputers

M16C / 62P Group

SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER

Under

development

Preliminary Specifications Rev.1.0

Specifications in this manual are tentative and subject to change.

Watchdog timer start register (Note)

Symbol

Address

After reset

WDTS

000E16

Indeterminate

Function

The watchdog timer is initialized and starts counting after a write instruction to

this register. The watchdog timer value is always initialized to “7FFF16”

regardless of whatever value is written.

Note : Write to the WDTS register after the watchdog timer interrupt occurs.

Figure 1.12.2. WDC Register and WDTS Register

CPU

clock

Write to WDTS register

RESET

PM12 = 0

Watchdog timer

Set to

“7FFF16”

1/128

1/16

CM07 = 0

WDC7 = 1

CM07 = 0

WDC7 = 0

CM07 = 1

HOLD

1/2

Prescaler

PM12 = 1

Watchdog timer

interrupt request

Reset

PM22 = 0

PM22 = 1

Ring oscillator clock

Figure 1.12.1. Watchdog Timer Block Diagram

Watchdog timer control register

Symbol

Address

After reset

WDC

000F16

00XXXXXX2(Note2)

Function

Bit symbol

High-order bit of watchdog timer

WDC7

Bit name

Prescaler select bit

0 : Divided by 16

1 : Divided by 128

Reserved bit

Must set to “0”

Cold start / warm start

discrimination flag (Note 1)

0 : Cold start

1 : Warm start

WDC5

Note 1: The WDC5 bit is always “1” (warm start) no matter how it is set by writing a “0” or “1”.

Note 2: The WDC5 bit is “0” (cold start) immediately after power-on. It can only be set to “1” in a program. It is set

to “0” when the input voltage at the VCC1 pin drops to Vdet2 or less while the VC25 bit in the VCR2 register

is set to “1” (RAM retention limit detection circuit enable).

(b4-b0)

(b6)

Setting the PM22 bit to “1” results in the following conditions

• The ring oscillator starts oscillating, and the ring oscillator clock becomes the watchdog timer count

source.

• The CM10 bit of CM1 register is disabled against write. (Writing a “1” has no effect, nor is stop mode

entered.)

• The watchdog timer does not stop when in wait mode or hold state.

M16C/62P Datasheet(PDF) 97 Page - Mitsubishi Electric Semiconductor

M16C/62P Datasheet(HTML) 97 Page - Mitsubishi Electric Semiconductor

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

Datasheet Download

Link URL