Datasheet

921
32142D–06/2013
ATUC64/128/256L3/4U
35.10 Timing Characteristics
35.10.1 Startup, Reset, and Wake-up Timing
The startup, reset, and wake-up timings are calculated using the following formula:
Where and are found in Table 35-39. is the period of the CPU clock. If a
clock source other than RCSYS is selected as the CPU clock, the oscillator startup time,
, must be added to the wake-up time from the stop, deepstop, and static sleep
modes. Please refer to the source for the CPU clock in the ”Oscillator Characteristics” on page
905 for more details about oscillator startup times.
Note: 1. These values are based on simulation and characterization of other AVR microcontrollers manufactured in the same pro-
cess technology. These values are not covered by test limits in production.
35.10.2 RESET_N Timing
Note: 1. These values are based on simulation and characterization of other AVR microcontrollers manufactured in the same pro-
cess technology. These values are not covered by test limits in production.
tt
CONST
N
CPU
t
CPU
+=
t
CONST
N
CPU
t
CPU
t
OSCSTART
Table 35-39. Maximum Reset and Wake-up Timing
(1)
Parameter Measuring Max (in µs) Max
Startup time from power-up, using
regulator
Time from VDDIN crossing the V
POT+
threshold of
POR33 to the first instruction entering the decode
stage of CPU. VDDCORE is supplied by the internal
regulator.
2210 0
Startup time from power-up, no
regulator
Time from VDDIN crossing the V
POT+
threshold of
POR33 to the first instruction entering the decode
stage of CPU. VDDCORE is connected to VDDIN.
1810 0
Startup time from reset release
Time from releasing a reset source (except POR18,
POR33, and SM33) to the first instruction entering
the decode stage of CPU.
170 0
Wake-up
Idle
From wake-up event to the first instruction of an
interrupt routine entering the decode stage of the
CPU.
019
Frozen 0110
Standby 0110
Stop 27 + 116
Deepstop 27 + 116
Static 97 + 116
Wake-up from shutdown
From wake-up event to the first instruction entering
the decode stage of the CPU.
1180 0
t
CONST
N
CPU
t
OSCSTART
t
OSCSTART
t
OSCSTART
Table 35-40. RESET_N Waveform Parameters
(1)
Symbol Parameter Conditions Min Max Units
t
RESET
RESET_N minimum pulse length 10 ns