ATmega64 Atmel Corporation, ATmega64 Datasheet - Page 186

• Manufacturer Part Number: ATmega64
• Manufacturer: Atmel Corporation

Specifications of ATmega64

• Flash (kbytes): 64 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): 2048
• 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

Asynchronous
Operational Range
2490Q–AVR–06/10
The operational range of the Receiver is dependent on the mismatch between the received bit
rate and the internally generated baud rate. If the Transmitter is sending frames at too fast or too
slow bit rates, or the internally generated baud rate of the receiver does not have a similar (see
Table
The following equations can be used to calculate the ratio of the incoming data rate and internal
receiver baud rate.
D
S
S
S
R
Table 75
that Normal Speed mode has higher toleration of baud rate variations.
F
M
slow
Sum of character size and parity size (D = 5 to 10 bit)
Samples per bit. S = 16 for Normal Speed mode and S = 8 for Double Speed
mode.
First sample number used for majority voting. S
for Double Speed mode.
Middle sample number used for majority voting. S
S
is the ratio of the slowest incoming data rate that can be accepted in relation to the
receiver baud rate. R
accepted in relation to the receiver baud rate.
75) base frequency, the Receiver will not be able to synchronize the frames to the start bit.
M
R
= 5 for Double Speed mode.
and
slow
Table 76
=
------------------------------------------ -
S 1
–
(
D
+
list the maximum Receiver baud rate error that can be tolerated. Note
+
D S ⋅
1
fast
)S
+
is the ratio of the fastest incoming data rate that can be
S
F
F
R
= 8 for Normal Speed and S
M
fast
= 9 for Normal Speed and
=
-----------------------------------
(
D
(
+
D
1
+
)S
ATmega64(L)
2
)S
+
S
M
F
= 4
186