ATxmega128B1 Atmel Corporation, ATxmega128B1 Datasheet - Page 312

• Manufacturer Part Number: ATxmega128B1
• Manufacturer: Atmel Corporation

Specifications of ATxmega128B1

• Flash (kbytes): 128 Kbytes
• Pin Count: 100
• Max. Operating Frequency: 32 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 16
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 53
• Ext Interrupts: 53
• Usb Transceiver: 1
• Usb Speed: Full Speed
• Usb Interface: Device
• Spi: 3
• Twi (i2c): 1
• Uart: 2
• Segment Lcd: 160
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 16
• Adc Resolution (bits): 12
• Adc Speed (ksps): 2000
• Analog Comparators: 4
• Resistive Touch Screen: No
• Temp. Sensor: Yes
• Crypto Engine: AES/DES
• Sram (kbytes): 8
• Eeprom (bytes): 2048
• Self Program Memory: YES
• Dram Memory: No
• Nand Interface: No
• Picopower: Yes
• Temp. Range (deg C): -40 to 85
• I/o Supply Class: 1.6 to 3.6
• Operating Voltage (vcc): 1.6 to 3.6
• Fpu: No
• Mpu / Mmu: no / no
• Timers: 3
• Output Compare Channels: 10
• Input Capture Channels: 10
• Pwm Channels: 10
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: Yes

8291A–AVR–10/11
Table 24-6.
• Bit 6:4 – CLKDIV[2:0]: LCD Clock Division
The CLKDIV bit-field defines the division ratio in the clock divider. The various selections are
shown in
Table 24-7.
Note that when using 1/3 duty, the frame rate is increased by 33% compared to the values listed
above.
Table 24-8.
CLKDIV[2:0]
clk
32.768kHz
32.768kHz
32.768kHz
32.768kHz
PRESC
0
1
LCD
0 0 0
0 0 1
0 1 0
0 1 1
1 0 0
1 0 1
1 1 0
1 1 1
Frame rate equation:
Where:
Table 24-7 on page
Output From Ripple Counter
N = prescaler divider (8 or 16).
K = 8 for 1/4, 1/2 and static duty.
K = 6 for 1/3 duty.
Static
L CD Prescaler Selection
LCD clock divider (1/4 Duty)
Example of frame rate calculation
Duty
1/2
1/4
1/3
Divided by
clk
clk
1
2
3
4
5
6
7
8
clk
K
8
8
6
8
LCD
LCD
LCD
/ 16
PRESC
/ N
/ 8
FrameRate
1
1
1
1
312. This Clock Divider gives extra flexibility in frame rate setting.
166.667 Hz
83.333 Hz
71.429 Hz
62.5 Hz
500 Hz
250 Hz
125 Hz
100 Hz
N=8
F(clk
16
16
16
16
N
=
LCD
CLKDIV[2:0]
-------------------------------------------------------------- -
(
) = 32 kHz
K
F(clk
×
4
4
4
4
Frame Rates ( CLKDIV[2:0] = 0, DUTY =
N
83.333 Hz
41.667 Hz
35.714 Hz
31.25 Hz
62.5 Hz
LCD
500 Hz
250 Hz
250 Hz
125 Hz
F clk
×
50 Hz
N=16
Frame Rate (1/4 Duty)
(
(
) = 32kHz
1
Atmel AVR XMEGA B
+
LCD
CLKDIV
32768 / ( 6 x 16 x ( 1 + 4 ) ) = 68.267Hz
32768 / ( 8 x 16 x ( 1 + 4 ) ) = 51.2Hz
32768 / ( 8 x 16 x ( 1 + 4 ) ) = 51.2Hz
32768 / ( 8 x 16 x ( 1 + 4 ) ) = 51.2Hz
)
170.667 Hz
85.333 Hz
73.143 Hz
)
102.4 Hz
)
512 Hz
256 Hz
128 Hz
64 Hz
N=8
F(clk
Frame rate
F(clk
LCD
LCD
) = 32768 Hz
512 Hz
256 Hz
) = 32768Hz
42.667 Hz
36.671 Hz
85.333 Hz
51.2 Hz
256 Hz
128 Hz
64 Hz
32 Hz
N=16
1
/
4
)
312