ATtiny24-20SSU datasheet(29/236 Pages) ATMEL

29 / 236 page

8006H–AVR–10/09

ATtiny24/44/84

Notes:

1. This option should not be used with crystals, only with ceramic resonators.

The Oscillator can operate in three different modes, each optimized for a specific frequency

range. The operating mode is selected by fuses CKSEL3..1 as shown in Table 6-9.

The CKSEL0 Fuse together with the SUT1..0 Fuses select the start-up times as shown in Table

6-10.

Notes:

1. When the BOD has been disabled by software, the wake-up time from sleep mode will be

approximately 60µs to ensure that the BOD is working correctly before the MCU continues

executing code.

2. These options should only be used when not operating close to the maximum frequency of the

device, and only if frequency stability at start-up is not important for the application. These

options are not suitable for crystals.

3. These options are intended for use with ceramic resonators and will ensure frequency stability

at start-up. They can also be used with crystals when not operating close to the maximum fre-

quency of the device, and if frequency stability at start-up is not important for the application.

Table 6-9.

Crystal Oscillator Operating Modes

CKSEL3..1

Frequency Range (MHz)

Recommended C1 and C2 Value (pF)

100(1)

0.4 - 0.9

–

101

0.9 - 3.0

12 - 22

110

3.0 - 8.0

12 - 22

111

8.0 -

12 - 22

Table 6-10.

Start-up Times for the Crystal Oscillator Clock Selection

CKSEL0

SUT1..0

Start-up Time from

Power-down(1)

Additional Delay

from Reset

Recommended Usage

258 CK(2)

14CK + 4 ms

Ceramic resonator,

fast rising power

258 CK(2)

14CK + 64 ms

Ceramic resonator,

slowly rising power

010

1K CK(3)

14CK

Ceramic resonator,

BOD enabled

011

1K CK(3)

14CK + 4 ms

Ceramic resonator,

fast rising power

100

1K CK(3)

14CK + 64 ms

Ceramic resonator,

slowly rising power

16K CK

14CK

Crystal Oscillator,

BOD enabled

16K CK

14CK + 4 ms

Crystal Oscillator,

fast rising power

16K CK

14CK + 64 ms

Crystal Oscillator,

slowly rising power

ATtiny24-20SSU Datasheet(PDF) 29 Page - ATMEL Corporation

ATtiny24-20SSU Datasheet(HTML) 29 Page - ATMEL Corporation

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

Datasheet Download

Link URL