ATmega644 Atmel Corporation, ATmega644 Datasheet - Page 298

• Manufacturer Part Number: ATmega644
• Manufacturer: Atmel Corporation

Specifications of ATmega644

• Flash (kbytes): 64 Kbytes
• Pin Count: 44
• Max. Operating Frequency: 20 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 16
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 32
• Ext Interrupts: 32
• Usb Speed: No
• Usb Interface: No
• Spi: 3
• Twi (i2c): 1
• Uart: 1
• 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): 2048
• 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: 6
• Input Capture Channels: 1
• Pwm Channels: 6
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: Yes

298
ATmega644
Figure 25-9. Parallel Programming Timing, Reading Sequence (within the Same Page) with
Note:
Table 25-14. Parallel Programming Characteristics, V
Symbol
V
I
t
t
t
t
t
t
t
t
t
t
t
t
t
t
t
t
t
PP
DVXH
XLXH
XHXL
XLDX
XLWL
XLPH
PLXH
BVPH
PHPL
PLBX
WLBX
PLWL
BVWL
WLWH
WLRL
WLRH
WLRH_CE
PP
XTAL1
DATA
BS1
XA0
XA1
OE
1. The timing requirements shown in
reading operation.
Parameter
Programming Enable Voltage
Programming Enable Current
Data and Control Valid before XTAL1 High
XTAL1 Low to XTAL1 High
XTAL1 Pulse Width High
Data and Control Hold after XTAL1 Low
XTAL1 Low to WR Low
XTAL1 Low to PAGEL high
PAGEL low to XTAL1 high
BS1 Valid before PAGEL High
PAGEL Pulse Width High
BS1 Hold after PAGEL Low
BS2/1 Hold after WR Low
PAGEL Low to WR Low
BS2/1 Valid to WR Low
WR Pulse Width Low
WR Low to RDY/BSY Low
WR Low to RDY/BSY High
WR Low to RDY/BSY High for Chip Erase
Timing Requirements
ADDR0 (Low Byte)
LOAD ADDRESS
(LOW BYTE)
t
XLOL
t
OLDV
(1)
(1)
(LOW BYTE)
DATA (Low Byte)
READ DATA
Figure 25-7
t
BVDV
(2)
(that is, t
CC
= 5V ±10%
(HIGH BYTE)
READ DATA
DATA (High Byte)
DVXH
11.5
Min
200
150
150
150
150
, t
3.7
7.5
67
67
67
67
67
67
67
0
0
0
XHXL
t
OHDZ
, and t
Typ
LOAD ADDRESS
XLDX
(LOW BYTE)
ADDR1 (Low Byte)
Max
12.5
250
4.5
) also apply to
1
9
2593N–AVR–07/10
Units
μA
ms
ns
μs
V