ATMEGA16-16AU SL602 Atmel, ATMEGA16-16AU SL602 Datasheet - Page 255

• Manufacturer Part Number: ATMEGA16-16AU SL602
• Manufacturer: Atmel

Programming Time for
Flash when using SPM
2466T–AVR–07/10
A Flash program corruption can be caused by two situations when the voltage is too low. First, a
regular write sequence to the Flash requires a minimum voltage to operate correctly. Secondly,
the CPU itself can execute instructions incorrectly, if the supply voltage for executing instructions
is too low.
Flash corruption can easily be avoided by following these design recommendations (one is
sufficient):
1. If there is no need for a Boot Loader update in the system, program the Boot Loader Lock
2. Keep the AVR RESET active (low) during periods of insufficient power supply voltage.
3. Keep the AVR core in Power-down Sleep mode during periods of low V
The Calibrated RC Oscillator is used to time Flash accesses.
gramming time for Flash accesses from the CPU.
Table 99. SPM Programming Time.
Symbol
Flash write (Page Erase, Page
Write, and write Lock bits by SPM)
bits to prevent any Boot Loader software updates.
This can be done by enabling the internal Brown-out Detector (BOD) if the operating volt-
age matches the detection level. If not, an external low V
be used. If a reset occurs while a write operation is in progress, the write operation will be
completed provided that the power supply voltage is sufficient.
vent the CPU from attempting to decode and execute instructions, effectively protecting
the SPMCR Register and thus the Flash from unintentional writes.
Min Programming Time
3.7 ms
CC
Max Programming Time
Reset Protection circuit can
Table 99
ATmega16(L)
4.5 ms
shows the typical pro-
CC
. This will pre-
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