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2 configuration of watchdog timer, Configuration of watchdog timer – FUJITSU F2MCTM-16LX User Manual

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CHAPTER 12 WATCHDOG TIMER

12.2

Configuration of Watchdog Timer

The watchdog timer consists of the following blocks:
• Count clock selector
• Watchdog timer counter (2-bit counter)
• Watchdog reset generator
• Counter clear control circuit
• Watchdog timer control register (WDTC)

Block Diagram of Watchdog Timer

Figure 12.2-1 Block Diagram of Watchdog Timer

Ч

2

1

Ч

2

2

Ч

2

11

Ч

2

12

Ч

2

13

Ч

2

14

Ч

2

15

Ч

2

16

Ч

2

17

Ч

2

18

Ч

2

10

Ч

2

9

Ч

2

8

⋅ ⋅ ⋅

2

SRST

WT1 WT0

WTE

PONR

WRST ERST

WDCS

Ч

2

1

Ч

2

2

Ч

2

8

Ч

2

9

Ч

2

10

Ч

2

11

Ч

2

12

Ч

2

13

Ч

2

14

Ч

2

15

Ч

2

7

Ч

2

6

Ч

2

5

⋅ ⋅ ⋅

4

4

Counter
clear control
circuit

Watchdog timer control register (WDTC)

Watch timer control register (WTC)

Watchdog reset
generation
circuit

2-bit
counter

Count clock
selector

Generation of reset

Shift to sleep mode

(Timebase timer counter)

(Watch counter)

HCLK : Oscillation clock
SCLK : Sub clock
* : SCLK is 2 division or 4 division of the clock inputted to the low-speed oscillation pin (X0A and X1A) or

internal CR oscillation clock. The division ratio is set by the SCDS bit of the PLL/subclock control
register (PSCCR). (See "CHAPTER 5 CLOCKS".)

Main clock
(2 division of HCLK)

Shift to timebase

timer mode

Shift to watch mode

Shift to stop mode

To internal
reset
generation
circuit

Watchdog timer

Start up

Clear

Sub clock
SCLK*