AT90CAN32 Automotive Atmel Corporation, AT90CAN32 Automotive Datasheet - Page 236

• Manufacturer Part Number: AT90CAN32 Automotive
• Manufacturer: Atmel Corporation

Specifications of AT90CAN32 Automotive

• Flash (kbytes): 32 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
• Can: 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): 2
• Eeprom (bytes): 1024
• Self Program Memory: YES
• Dram Memory: No
• Nand Interface: No
• Picopower: No
• Temp. Range (deg C): -40 to 125
• 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

19.2.3.2
19.2.3.3
19.2.3.4
19.2.3.5
19.2.3.6
19.2.3.7
236
AT90CAN32/64/128
Synchronization Segment
Propagation Time Segment
Phase Segment 1
Sample Point
Phase Segment 2
Information Processing Time
Transmission Point
Figure 19-3. CAN Bit Construction
The first segment is used to synchronize the various bus nodes.
On transmission, at the start of this segment, the current bit level is output. If there is a bit state
change between the previous bit and the current bit, then the bus state change is expected to
occur within this segment by the receiving nodes.
This segment is used to compensate for signal delays across the network.
This is necessary to compensate for signal propagation delays on the bus line and through the
transceivers of the bus nodes.
Phase Segment 1 is used to compensate for edge phase errors.
This segment may be lengthened during re-synchronization.
The sample point is the point of time at which the bus level is read and interpreted as the value
of the respective bit. Its location is at the end of Phase Segment 1 (between the two Phase
Segments).
This segment is also used to compensate for edge phase errors.
This segment may be shortened during re-synchronization, but the length has to be at least as
long as the Information Processing Time (IPT) and may not be more than the length of Phase
Segment 1.
It is the time required for the logic to determine the bit level of a sampled bit.
Time Quantum
CAN Frame
(producer)
(producer)
(consumer)
Segments
(producer)
(producer)
Segments
SYNC_SEG
propagation
delay
SYNC_SEG
PROP_SEG
PROP_SEG
Nominal CAN Bit Time
PHASE_SEG_1
PHASE_SEG_1
PHASE_SEG_2
Sample Point
PHASE_SEG_2
7682C–AUTO–04/08