ATmega64C1 Automotive Atmel Corporation, ATmega64C1 Automotive Datasheet - Page 170

• Manufacturer Part Number: ATmega64C1 Automotive
• Manufacturer: Atmel Corporation

Specifications of ATmega64C1 Automotive

• Flash (kbytes): 64 Kbytes
• Pin Count: 32
• Max. Operating Frequency: 16 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 12
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 27
• Ext Interrupts: 27
• Usb Speed: No
• Usb Interface: No
• Spi: 1
• Uart: 1
• Can: 1
• Lin: 1
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 11
• Adc Resolution (bits): 10
• Adc Speed (ksps): 125
• Analog Comparators: 4
• Resistive Touch Screen: No
• Dac Channels: 1
• Dac Resolution (bits): 10
• Temp. Sensor: Yes
• 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 150
• I/o Supply Class: 2.7 to 5.5
• Operating Voltage (vcc): 2.7 to 5.5
• Fpu: No
• Mpu / Mmu: no / no
• Timers: 2
• Output Compare Channels: 4
• Input Capture Channels: 1
• Pwm Channels: 4
• 32khz Rtc: No
• Calibrated Rc Oscillator: Yes

16.2.2.2
Figure 16-2. CAN Extended Frames
16.2.2.3
16.2.3
16.2.3.1
170
Bus Idle
Interframe
Bus Idle
Interframe
Data Frame
Remote Frame
Space
Space
Atmel ATmega16/32/64/M1/C1
SOF
SOF
SOF
SOF
CAN Bit Timing
CAN Extended Frame
Format Co-existence
Bit Construction
11-bit base identifier
11-bit base identifier
IDT28..18
IDT28..18
SRR IDE
SRR IDE
A message in the CAN extended frame format is likely the same as a message in CAN stan-
dard frame format. The difference is the length of the identifier used. The identifier is made up
of the existing 11-bit identifier (base identifier) and an 18-bit extension (identifier extension).
The distinction between CAN standard frame format and CAN extended frame format is made
by using the IDE bit which is transmitted as dominant in case of a frame in CAN standard
frame format, and transmitted as recessive in the other case.
As the two formats have to co-exist on one bus, it is laid down which message has higher pri-
ority on the bus in the case of bus access collision with different formats and the same
identifier / base identifier: The message in CAN standard frame format always has priority over
the message in extended format.
There are three different types of CAN modules available:
To ensure correct sampling up to the last bit, a CAN node needs to re-synchronize throughout
the entire frame. This is done at the beginning of each message with the falling edge SOF and
on each recessive to dominant edge.
One CAN bit time is specified as four non-overlapping time segments. Each segment is con-
structed from an integer multiple of the Time Quantum. The Time Quantum or TQ is the
smallest discrete timing resolution used by a CAN node.
Arbitration
Arbitration
Field
Field
– 2.0A - Considers 29 bit ID as an error
– 2.0B Passive - Ignores 29 bit ID messages
– 2.0B Active - Handles both 11 and 29 bit ID Messages
18-bit identifier extension
18-bit identifier extension
ID17..0
ID17..0
RTR
RTR
r1
r1
r0
r0
Control
Control
Field
Field
4-bit DLC
4-bit DLC
DLC4..0
DLC4..0
15-bit CRC
CRC
Field
0 - 8 bytes
Data
Field
CRC
del.
ACK
Field
ACK
ACK
del.
15-bit CRC
End of
Frame
7 bits
CRC
Field
CRC
Intermission
del.
3 bits
ACK
ACK
Field
Interframe
ACK
Space
del.
(Indefinite)
Bus Idle
End of
Frame
7 bits
7647G–AVR–09/11
Intermission
3 bits
Interframe
Space
(Indefinite)
Bus Idle