ATTIny2313-16MI ATMEL Corporation, ATTIny2313-16MI Datasheet - Page 27

• Manufacturer Part Number: ATTIny2313-16MI
• Description: 8-bit AVR Microcontroller with 2K Bytes In-System Programmable Flash
• Manufacturer: ATMEL Corporation

External Clock
2543C–AVR–12/03
To drive the device from an external clock source, XTAL1 should be driven as shown in
Figure 13. To run the device on an external clock, the CKSEL Fuses must be pro-
grammed to “0000”.
Figure 13. External Clock Drive Configuration
When this clock source is selected, start-up times are determined by the SUT Fuses as
shown in Table 10.
Table 9. Crystal Oscillator Clock Frequency
Table 10. Start-up Times for the External Clock Selection
When applying an external clock, it is required to avoid sudden changes in the applied
clock frequency 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.
CKSEL3..0
0000 - 0001
SUT1..0
00
01
10
11
Start-up Time from Power-
down and Power-save
EXTERNAL
6 CK
6 CK
6 CK
SIGNAL
CLOCK
NC
Frequency Range
0 - 16 MHz
Additional Delay from
Reset (V
Reserved
14CK + 4.1 ms
14CK + 65 ms
14CK
XTAL2
XTAL1
GND
CC
= 5.0V)
ATtiny2313/V
BOD enabled
Fast rising power
Slowly rising power
Recommended Usage
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