ATMEGA128-16AI Atmel, ATMEGA128-16AI Datasheet - Page 40

• Manufacturer Part Number: ATMEGA128-16AI
• Description: IC AVR MCU 128K 16MHZ 64-TQFP
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA128-16AI

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 16MHz
• Connectivity: EBI/EMI, I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 53
• Program Memory Size: 128KB (64K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 4K x 8
• Ram Size: 4K x 8
• Voltage - Supply (vcc/vdd): 4.5 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 64-TQFP, 64-VQFP
• For Use With: ATSTK501 - ADAPTER KIT FOR 64PIN AVR MCU
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Other names: Q1167170A

External RC
Oscillator
40
ATmega128
For timing insensitive applications, the External RC configuration shown in
used. The frequency is roughly estimated by the equation f = 1/(3RC). C should be at least
22pF. By programming the CKOPT fuse, the user can enable an internal 36pF capacitor
between XTAL1 and GND, thereby removing the need for an external capacitor. For more infor-
mation on Oscillator operation and details on how to choose R and C, refer to the External RC
Oscillator application note.
Figure 20. External RC Configuration
The Oscillator can operate in four different modes, each optimized for a specific frequency
range. The operating mode is selected by the fuses CKSEL3..0 as shown in
Table 11. External RC Oscillator Operating Modes
When this Oscillator is selected, start-up times are determined by the SUT fuses as shown in
Table
Table 12. Start-Up Times for the External RC Oscillator Clock Selection
Note:
SUT1..0
00
01
10
11
12.
1. This option should not be used when operating close to the maximum frequency of the device.
CKSEL3..0
Start-up Time from
Power-down and
0101
0110
0111
1000
Power-save
6 CK
18 CK
18 CK
18 CK
(1)
C
R
V
CC
Additional Delay
(V
from Reset
CC
4.1ms
4.1ms
65ms
NC
= 5.0V)
–
Frequency Range (MHz)
Recommended Usage
BOD enabled
Fast rising power
Slowly rising power
Fast rising power or BOD enabled
8.0 - 12.0
0.1 - 0.9
0.9 - 3.0
3.0 - 8.0
XTAL2
XTAL1
GND
Table
Figure 20
2467V–AVR–02/11
11.
can be