ata6616 ATMEL Corporation, ata6616 Datasheet - Page 55

• Manufacturer Part Number: ata6616
• Description: Microcontroller With Lin Transceiver, 5v Regulator And Watchdog
• Manufacturer: ATMEL Corporation

4.5.2.6
9132A–AUTO–10/08
DRAFT
External Clock
Figure 4-12. Low-frequency Crystal Oscillator Connections
When this oscillator is selected, start-up times are determined by the SUT fuses or by CSUT
field as shown in
Table 4-11.
To drive the device from this external clock source, CLKI should be driven as shown in
4-13. To run the device on an external clock, the CKSEL Fuses or CSEL field must be pro-
grammed as shown in
Figure 4-13. External Clock Drive Configuration
When this clock source is selected, start-up times are determined by the SUT Fuses or CSUT
field as shown in
This external clock can be used by the asynchronous timer if the high or low frequency Crystal
Oscillator is not running
timer is then able to enable this input.
Notes:
CSUT1..0
SUT1..0
00
01
10
11
1. Flash Fuse bits
2. CLKSELR register bits
3. These options should only be used if frequency stability at start-up is not important for the
(1)
(2)
application
Start-up Times for the Low Frequency Crystal Oscillator Clock Selection
Start-up Time from
Table
Table
Power-down/save
32K (32768) CK
1K (1024) CK
1K (1024) CK
Table 4-4 on page
4-11.
4-12.
(See ”Enable/Disable Clock Source” on page
12-22 pF capacitors may be necessary if parasitic
impedance (pads, wires & PCB) is very low.
(3)
(3)
ATA6616/ATA6617 [Preliminary]
External
32.768 KHz
Signal
Clock
Additional Delay from
~
C1=12-22 pF
C2=12-22 pF
Reset (Vcc = 5.0V)
50.
4.1 ms
65 ms
65 ms
Reserved
(XTAL2)
(XTAL1)
(CLKO)
CLKI
GND
XTAL2
XTAL1
GND
Fast rising power or BOD enabled
Stable frequency at start-up
Recommended Usage
Slowly rising power
58.). The asynchronous
Figure
55