Добавил:
Upload Опубликованный материал нарушает ваши авторские права? Сообщите нам.
Вуз: Предмет: Файл:
AVR / datasheets / attiny_25_45_85_Automotive.pdf
Скачиваний:
174
Добавлен:
20.03.2015
Размер:
1.67 Mб
Скачать

ATtiny25/45/85 Auto

When the BOD is enabled, and VCC decreases to a value below the trigger level (VBOT- in Figure 8-5), the Brown-out Reset is immediately activated. When VCC increases above the trigger level

(VBOT+ in Figure 8-5), the delay counter starts the MCU after the Time-out period tTOUT has expired.

The BOD circuit will only detect a drop in VCC if the voltage stays below the trigger level for longer than tBOD given in Table 8-1.

Figure 8-5. Brown-out Reset During Operation

VCC

VBOT+

 

VBOT-

RESET

 

TIME-OUT

tTOUT

INTERNAL

 

RESET

 

8.0.6Watchdog Reset

When the Watchdog times out, it will generate a short reset pulse of one CK cycle duration. On

the falling edge of this pulse, the delay timer starts counting the Time-out period tTOUT. Refer to page 41 for details on operation of the Watchdog Timer.

Figure 8-6. Watchdog Reset During Operation

CC

CK

8.0.7MCU Status Register – MCUSR

The MCU Status Register provides information on which reset source caused an MCU Reset.

Bit

7

6

5

4

3

2

1

0

 

 

WDRF

BORF

EXTRF

PORF

MCUSR

 

 

 

 

 

 

 

 

 

 

Read/Write

R

R

R

R

R/W

R/W

R/W

R/W

Initial Value

0

0

0

0

 

See Bit Description

 

 

• Bits 7..4 – Res: Reserved Bits

39

7598C–AVR–09/06

Соседние файлы в папке datasheets