ATA6616-P3PW Atmel, ATA6616-P3PW Datasheet - Page 50

• Manufacturer Part Number: ATA6616-P3PW
• Description: TXRX MULTICHIP MOD LIN SIP 38QFN
• Manufacturer: Atmel
• Series: AVR® ATA66 LIN-SBCr

Specifications of ATA6616-P3PW

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 16MHz
• Connectivity: I²C, LIN, SPI, UART/USART, USI
• Peripherals: Brown-out Detect/Reset, POR, PWM, Temp Sensor, WDT
• Number Of I /o: 16
• Program Memory Size: 8KB (8K x 8)
• Program Memory Type: FLASH
• Eeprom Size: 512 x 8
• Ram Size: 512 x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Data Converters: A/D 11x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 125°C
• Package / Case: 38-VQFN
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

4.5.2.1
4.5.2.2
50
Atmel ATA6616/ATA6617
Default Clock Source
Calibrated Internal RC Oscillator
When the CPU wakes up from Power-down or Power-save, or when a new clock source is
enabled by the dynamic clock switch circuit, the selected clock source is used to time the
start-up, ensuring stable oscillator operation before instruction execution starts.
When the CPU starts from reset, there is an additional delay allowing the power to reach a sta-
ble level before commencing normal operation. The Watchdog Oscillator is used for timing this
real-time part of the start-up sequence. The number of WDT Oscillator cycles used for each
time-out is shown in
Table 4-6.
At reset, the CKSEL and SUT fuse settings are copied into the CLKSELR register. The device
will then use the clock source and the start-up timings defined by the CLKSELR bits
(CSEL3..0 and CSUT1:0).
The device is shipped with CKSEL Fuses = 0010
grammed. The default clock source setting is therefore the Internal RC Oscillator running at 8
MHz with the longest start-up time and an initial system clock divided by 8. This default setting
ensures that all users can make their desired clock source setting using an In-System or
High-voltage Programmer. This set-up must be taken into account when using ISP tools.
By default, the Internal RC Oscillator provides an approximate 8.0 MHz clock. Though voltage
and temperature dependent, this clock can be accurately calibrated by the user. See
4-81 on page 269
If selected, it can operate without external components. At reset, hardware loads the pre-pro-
grammed calibration value into the OSCCAL Register and thereby automatically configuring
the RC Oscillator. The accuracy of this calibration is shown as Factory calibration in
4-81 on page
By adjusting the OSCCAL register in software, see
ibration Register” on page
the factory calibration. The accuracy of this calibration is shown as User calibration in
4-81 on page
The Watchdog Oscillator will still be used for the Watchdog Timer and for the Reset Time-out
even when this Oscillator is used as the device clock. For more information on the pre-pro-
grammed calibration value, see the section
Typ. Time-out (Vcc = 5.0V)
4.1ms
65ms
269.
269.
Number of Watchdog Oscillator Cycles
and
Table
Section 4.25.7 “Internal Oscillator Speed” on page 288
4-6.
61, it is possible to get a higher calibration accuracy than by using
Typ. Time-out (Vcc = 5.0V)
Section 4.22.4 “Calibration Byte” on page
4.3ms
69ms
b
, SUT Fuses = 10
Section 4.5.5.1 “OSCCAL – Oscillator Cal-
b
, and CKDIV8 Fuse pro-
Number of Cycles
8K (8,192)
512
for more details.
9132D–AUTO–12/10
252.
Table
Table
Table