ATMEGA649A-AU Atmel, ATMEGA649A-AU Datasheet - Page 252

IC MCU AVR 64K FLASH 64TQFP

ATMEGA649A-AU

Manufacturer Part Number
ATMEGA649A-AU
Description
IC MCU AVR 64K FLASH 64TQFP
Manufacturer
Atmel
Series
AVR® ATmegar
Datasheets

Specifications of ATMEGA649A-AU

Core Processor
AVR
Core Size
8-Bit
Speed
16MHz
Connectivity
SPI, UART/USART, USI
Peripherals
Brown-out Detect/Reset, LCD, POR, PWM, WDT
Number Of I /o
54
Program Memory Size
64KB (32K x 16)
Program Memory Type
FLASH
Eeprom Size
2K x 8
Ram Size
4K x 8
Voltage - Supply (vcc/vdd)
1.8 V ~ 5.5 V
Data Converters
A/D 8x10b
Oscillator Type
Internal
Operating Temperature
-40°C ~ 85°C
Package / Case
64-TQFP
Processor Series
ATmega
Core
AVR
Data Bus Width
8 bit
Data Ram Size
4 KB
Interface Type
SPI, USART
Maximum Clock Frequency
16 MHz
Number Of Programmable I/os
54
Number Of Timers
3
Operating Supply Voltage
3.3 V
Maximum Operating Temperature
+ 85 C
Mounting Style
SMD/SMT
Minimum Operating Temperature
- 40 C
Operating Temperature Range
- 40 C to + 85 C
Lead Free Status / RoHS Status
Lead free / RoHS Compliant

Available stocks

Company
Part Number
Manufacturer
Quantity
Price
Part Number:
ATMEGA649A-AU
Manufacturer:
Atmel
Quantity:
10 000
Part Number:
ATMEGA649A-AUR
Manufacturer:
Atmel
Quantity:
10 000
23.5.4
8284A–AVR–10/10
LCDCCR – LCD Contrast Control Register
is increased with 33% when Frame Rate Register is constant. Example of frame rate calculation
is shown in
Table 23-6.
• Bits 7:5 – LCDDC[2:0]: LDC Display Configuration
The LCDDC[2:0] bits determine the amount of time the LCD drivers are turned on for each volt-
age transition on segment and common pins. A short drive time will lead to lower power
consumption, but displays with high internal resistance may need longer drive time to achieve
satisfactory contrast. Note that the drive time will never be longer than one half prescaled LCD
clock period, even if the selected drive time is longer. When using static duty or blanking, drive
time will always be one half prescaled LCD clock period.
New values take effect immediately, and can cause small glitches in the display output. This can
be avoided by setting the LCDBL in LCDCRA, and wait to the next start of frame before chang-
ing LCDDC[2:0].
Table 23-7.
Note:
• Bit 4 – LCDMDT: LCD Maximum Drive Time
Writing this bit to one turns the LCD drivers on 100% all the time, regardless of the drive time
configured by LCDDC[2:0].
Bit
(0xE7)
Read/Write
Initial Value
clk
4 MHz
4 MHz
32.768 kHz
32.768 kHz
ATmega169A/169PA/329A/329PA/649A/649P/3290A/3290PA/6490A/6490P
LCD
LCDDC2
The drive time will be longer dependent on oscillator startup time.
0
0
0
0
1
1
1
1
Table 23-6 on page
LCDDC2
Example of frame rate calculation
LCD Display Configuration
R/W
duty
7
0
Static
1/4
1/3
1/2
LCDDC1
R/W
K
8
6
8
8
6
0
LCDDC1
0
0
1
1
0
0
1
1
252.
LCDDC0
2048
2048
R/W
16
16
5
0
N
LCDNDT
R
4
0
LCDCD2:0
011
011
000
100
LCDDC0
LCDCC3
0
1
0
1
0
1
0
1
R/W
3
0
D
4
4
1
5
LCDCC2
R/W
2
0
Nominal drive time
300 µs
70 µs
150 µs
450 µs
575 µs
850 µs
1150 µs
50% of clk
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
LCDCC1
R/W
1
0
LCD_PS
LCDCC0
R/W
0
0
LCDCCR
252

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