ATA5771_09 ATMEL [ATMEL Corporation], ATA5771_09 Datasheet - Page 83

• Manufacturer Part Number: ATA5771_09
• Description: Microcontroller with UHF ASK/FSK Transmitter
• Manufacturer: ATMEL [ATMEL Corporation]

30
ATtiny24/44/84
Figure 7-3.
When this clock source is selected, start-up times are determined by the SUT Fuses as shown in
Table 7-8 on page
Table 7-8.
When applying an external clock, it is required to avoid sudden changes in the applied clock fre-
quency to ensure stable operation of the MCU. A variation in frequency of more than 2% from
one clock cycle to the next can lead to unpredictable behavior. It is required to ensure that the
MCU is kept in Reset during such changes in the clock frequency.
Note that the System Clock Prescaler can be used to implement run-time changes of the internal
clock frequency while still ensuring stable operation. See to
31
SUT1..0
for details.
00
01
10
11
Start-up Time from Power-
External Clock Drive Configuration
Start-up Times for the External Clock Selection
down and Power-save
30.
6 CK
6 CK
6 CK
EXTERNAL
SIGNAL
CLOCK
Additional Delay from
Reserved
14CK + 64 ms
14CK + 4 ms
CLKI
GND
Reset
14CK
”System Clock Prescaler” on page
Fast rising power
BOD enabled
Slowly rising power
Recommended Usage
7701C–AVR–12/08