ATTINY15 ATMEL [ATMEL Corporation], ATTINY15 Datasheet - Page 13

• Manufacturer Part Number: ATTINY15
• Manufacturer: ATMEL [ATMEL Corporation]

ATtiny15L Reset Sources
1187D–12/01
The ATtiny15L has four sources of reset:
•
•
•
•
During reset, all I/O registers are then set to their initial values, and the program starts
execution from address $000. The instruction placed in address $000 must be an RJMP
(relative jump) instruction to the reset handling routine. If the program never enables an
interrupt source, the interrupt vectors are not used, and regular program code can be
placed at these locations. The circuit diagram in Figure 12 shows the reset logic. Table 4
and Table 5 define the timing and electrical parameters of the reset circuitry. Note that
the register file is unchanged by a reset.
Figure 12. Reset Logic
Power-on Reset. The MCU is reset when the supply voltage is below the Power-on
Reset threshold (V
External Reset. The MCU is reset when a low-level is present on the RESET pin for
more than 500 ns.
Watchdog Reset. The MCU is reset when the Watchdog Timer period expires, and
the Watchdog is enabled.
Brown-out Reset. The MCU is reset when the supply voltage V
Brown-out Reset threshold (V
BODLEVEL
BODEN
POR
CKSEL[1:0]
Power-on Reset
Tunable Internal
Reset Circuit
Reset Circuit
Brown-out
).
Watchdog
Watchdog
Oscillator
Oscillator
Circuit
Timer
BOT
).
CK
Register (MCUSR)
MCU Status
DATA BUS
Delay Counters
TIMEOUT
CC
ATtiny15L
is below the
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