ata6616 ATMEL Corporation, ata6616 Datasheet - Page 76

• Manufacturer Part Number: ata6616
• Description: Microcontroller With Lin Transceiver, 5v Regulator And Watchdog
• Manufacturer: ATMEL Corporation

4.7.1.6
4.7.1.7
76
ATA6616/ATA6617 [Preliminary]
Watchdog System Reset
MCU Status Register – MCUSR
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 t
page 77
Figure 4-21. Watchdog System Reset During Operation
The MCU Status Register provides information on which reset source caused an MCU reset.
• Bit 7..4 – Res: Reserved Bits
These bits are unused bits in the ATtiny167, and will always read as zero.
• Bit 3 – WDRF: Watchdog System Reset Flag
This bit is set if a Watchdog System Reset occurs. The bit is reset by a Power-on Reset, or by
writing a logic zero to the flag.
• Bit 2 – BORF: Brown-out Reset Flag
This bit is set if a Brown-out Reset occurs. The bit is reset by a Power-on Reset, or by writing a
logic zero to the flag.
• Bit 1 – EXTRF: External Reset Flag
This bit is set if an External Reset occurs. The bit is reset by a Power-on Reset, or by writing a
logic zero to the flag.
• Bit 0 – PORF: Power-on Reset Flag
This bit is set if a Power-on Reset occurs. The bit is reset only by writing a logic zero to the flag.
To make use of the Reset Flags to identify a reset condition, the user should read and then
Reset the MCUSR as early as possible in the program. If the register is cleared before another
reset occurs, the source of the reset can be found by examining the Reset Flags.
Bit
Read/Write
Initial Value
CC
for details on operation of the Watchdog Timer.
R
7
–
0
R
6
–
0
R
5
–
0
CK
R
4
–
0
DRAFT
WDRF
R/W
3
See Bit Description
BORF
R/W
2
EXTRF
R/W
1
PORF
R/W
9132A–AUTO–10/08
0
TOUT
. Refer to
MCUSR