Rainbow Electronics ATtiny15L - Manual (Page 13)

13
ATtiny15L
1187E–AVR–06/02
The most typical and general program setup for the Reset and Interrupt Vector
Addresses are:
Address Labels Code Comments
$000 rjmp RESET ; Reset handler
$001 rjmp EXT_INT0 ; IRQ0 handler
$002 rjmp PIN_CHANGE ; Pin change handler
$003 rjmp TIM1_CMP ; Timer1 compare match
$004 rjmp TIM1_OVF ; Timer1 overflow handler
$005 rjmp TIM0_OVF ; Timer0 overflow handler
$006 rjmp EE_RDY ; EEPROM Ready handler
$007 rjmp ANA_COMP ; Analog Comparator handler
$008 rjmp ADC ; ADC Conversion Handler
;
$009 MAIN: <instr> xxx ; Main program start
… … … …
ATtiny15L Reset Sources The ATtiny15L has four sources of Reset:
• Power-on Reset. The MCU is reset when the supply voltage is below the Power-on
Reset threshold (V
POR
).
• 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
CC
is below the
Brown-out Reset threshold (V
BOT
).
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.