AT90CAN128-16AE ATMEL Corporation, AT90CAN128-16AE Datasheet - Page 38

• Manufacturer Part Number: AT90CAN128-16AE
• Description: 8-bit Avr Microcontroller With 128K Bytes of Isp Flash And CAN Controller.flash (Kbytes) 128 Vcc (V) 2.7-5.5 EEPROM (Kbytes) 4 SRAM (bytes) 4K CAN (mess. Obj.) 15
• Manufacturer: ATMEL Corporation

Low-frequency
Crystal Oscillator
38
AT90CAN128
Table 8. Start-up Times for the Oscillator Clock Selection
Notes:
To use a 32.768 kHz watch crystal as the clock source for the device, the low-frequency
crystal Oscillator must be selected by setting the CKSEL Fuses to “0100”, “0101”,
“0110”, or “0111”. The crystal should be connected as shown in Figure 20. When this
Oscillator is selected, start-up times are determined by the SUT Fuses as shown in
Table 9 and CKSEL1..0 as shown in Table 10.
Table 9. Start-up Times for the Low-frequency Crystal Oscillator Clock Selection
CKSEL0
SUT1..0
00
01
10
11
0
0
0
0
1
1
1
1
1. These options should only be used when not operating close to the maximum fre-
2. These options are intended for use with ceramic resonators and will ensure fre-
quency of the device, and only if frequency stability at start-up is not important for the
application. These options are not suitable for crystals.
quency stability at start-up. They can also be used with crystals when not operating
close to the maximum frequency of the device, and if frequency stability at start-up is
not important for the application.
SUT1..0
Additional Delay from Reset (V
00
01
10
00
01
10
11
11
Start-up Time from
Power-down and
14CK + 4.1 ms
14CK + 65 ms
Power-save
258 CK
258 CK
1K CK
1K CK
1K CK
16K CK
16K CK
16K CK
14CK
(2)
(2)
(2)
(1)
(1)
CC
Reserved
= 5.0V)
Additional Delay
14CK + 4.1 ms
14CK + 4.1 ms
14CK + 4.1 ms
14CK + 65 ms
14CK + 65 ms
14CK + 65 ms
(V
from Reset
CC
14CK
14CK
= 5.0V)
Recommended Usage
Fast rising power or BOD enabled
Slowly rising power
Stable frequency at start-up
Recommended Usage
Ceramic resonator, fast
rising power
Ceramic resonator,
slowly rising power
Ceramic resonator,
BOD enabled
Ceramic resonator, fast
rising power
Ceramic resonator,
slowly rising power
Crystal Oscillator, BOD
enabled
Crystal Oscillator, fast
rising power
Crystal Oscillator,
slowly rising power
4250C–CAN–03/04