ATmega128A Atmel Corporation, ATmega128A Datasheet - Page 40

• Manufacturer Part Number: ATmega128A
• Manufacturer: Atmel Corporation

Specifications of ATmega128A

• Flash (kbytes): 128 Kbytes
• Pin Count: 64
• Max. Operating Frequency: 16 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 16
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 53
• Ext Interrupts: 8
• Usb Speed: No
• Usb Interface: No
• Spi: 1
• Twi (i2c): 1
• Uart: 2
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 8
• Adc Resolution (bits): 10
• Adc Speed (ksps): 15
• Analog Comparators: 1
• Resistive Touch Screen: No
• Temp. Sensor: No
• Crypto Engine: No
• Sram (kbytes): 4
• Eeprom (bytes): 4096
• Self Program Memory: YES
• Dram Memory: No
• Nand Interface: No
• Picopower: No
• Temp. Range (deg C): -40 to 85
• I/o Supply Class: 2.7 to 5.5
• Operating Voltage (vcc): 2.7 to 5.5
• Fpu: No
• Mpu / Mmu: no / no
• Timers: 4
• Output Compare Channels: 8
• Input Capture Channels: 2
• Pwm Channels: 7
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: Yes

8151H–AVR–02/11
capacitance, and the electromagnetic noise of the environment. Some initial guidelines for
choosing capacitors for use with crystals are given in
capacitor values given by the manufacturer should be used.
Figure 8-2.
The Oscillator can operate in three different modes, each optimized for a specific frequency
range. The operating mode is selected by the fuses CKSEL3:1 as shown in
Table 8-3.
Note:
The CKSEL0 fuse together with the SUT1:0 fuses select the start-up times as shown in
4.
Table 8-4.
CKOPT
CKSEL0
1
1
1
0
0
0
0
0
1
1. This option should not be used with crystals, only with ceramic resonators.
101, 110, 111
SUT1:0
CKSEL3:1
Crystal Oscillator Connections
Crystal Oscillator Operating Modes
Start-up Times for the Crystal Oscillator Clock Selection
00
01
10
11
00
101
110
111
(1)
Power-down and Power-
Start-up Time from
Frequency Range
258 CK
258 CK
1K CK
1K CK
1K CK
save
0.4 - 0.9
0.9 - 3.0
3.0 - 8.0
(MHz)
C2
C1
1.0 -
(2)
(2)
(2)
(1)
(1)
from Reset (V
Additional Delay
Recommended Range for Capacitors C1
Table
4.1ms
4.1ms
5.0V)
65ms
65ms
XTAL2
XTAL1
GND
–
and C2 for Use with Crystals
8-3. For ceramic resonators, the
CC
=
12 - 22pF
12 - 22pF
12 - 22pF
ATmega128A
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
–
Table
8-3.
Table 8-
40