ATmega329 Atmel Corporation, ATmega329 Datasheet - Page 242

• Manufacturer Part Number: ATmega329
• Manufacturer: Atmel Corporation

Specifications of ATmega329

• Flash (kbytes): 32 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: 54
• Ext Interrupts: 17
• Usb Speed: No
• Usb Interface: No
• Spi: 2
• Twi (i2c): 1
• Uart: 1
• Segment Lcd: 100
• 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): 2
• Eeprom (bytes): 1024
• Self Program Memory: YES
• Dram Memory: No
• Nand Interface: No
• Picopower: No
• Temp. Range (deg C): -40 to 85
• I/o Supply Class: 1.8 to 5.5
• Operating Voltage (vcc): 1.8 to 5.5
• Fpu: No
• Mpu / Mmu: no / no
• Timers: 3
• Output Compare Channels: 4
• Input Capture Channels: 1
• Pwm Channels: 4
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: Yes

242
ATmega329/3290/649/6490
Table 23-5.
The frame frequency can be calculated by the following equation:
Where:
This is a very flexible scheme, and users are encouraged to calculate their own table to investi-
gate the possible frame rates from the formula above. Note when using 1/3 duty the frame rate
is increased with 33% when Frame Rate Register is constant. Example of frame rate calculation
is shown in
Table 23-6.
clk
4MHz
4MHz
32.768kHz
32.768kHz
LCDCD2
LCD
0
0
0
0
1
1
1
1
N = prescaler divider (16, 64, 128, 256, 512, 1024, 2048, or 4096).
K = 8 for duty = 1/4, 1/2, and static.
K = 6 for duty = 1/3.
D = Division factor (see
Table
LCDCD1
duty
1/4
1/3
Static
1/2
LCD Clock Divide
Example of frame rate calculation
0
0
1
1
0
0
1
1
23-6.
K
8
6
8
8
LCDCD0
0
1
0
1
0
1
0
1
Table
2048
2048
16
16
N
divided by (D) :
Output from
23-5)
Prescaler
f
LCDCD2:0
frame
1
2
3
4
5
6
7
8
011
011
000
100
=
------------------------- -
(
K N D
f
clk
⋅
Duty = 1/4, gives a frame rate of:
LCD
clk
D
4
4
1
5
⋅
LCD
)
Frame Rate
4000000/(8*2048*4) = 61 Hz
4000000/(6*2048*4) = 81 Hz
32768/(8*16*1) = 256 Hz
32768/(8*16*5) = 51 Hz
= 32.768kHz, N = 16, and
85.3Hz
51.2Hz
42.7Hz
36.6Hz
256Hz
128Hz
64Hz
32Hz
2552K–AVR–04/11