ATMEGA64M1-AU Atmel, ATMEGA64M1-AU Datasheet - Page 166

• Manufacturer Part Number: ATMEGA64M1-AU
• Description: IC MCU AVR 64K FLASH 32TQFP
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA64M1-AU

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 16MHz
• Connectivity: CAN, LIN, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, Temp Sensor, WDT
• 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): 2.7 V ~ 5.5 V
• Data Converters: A/D 11x10b; D/A 1x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 32-TQFP, 32-VQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Number Of I /o: -
• Lead Free Status / Rohs Status: Details

Figure 19-3. CAN Bit Construction
19.3.3.2
19.3.3.3
19.3.3.4
19.3.3.5
19.3.3.6
19.3.3.7
166
Transmission Point
Time Quantum
CAN Frame
(producer)
(producer)
(consumer)
(producer)
(producer)
Segments
Segments
ATmega16M1/32M1/64M1
Synchronization Segment
Propagation Time Segment
Phase Segment 1
Sample Point
Phase Segment 2
Information Processing Time
SYNC_SEG
propagation
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.
The IPT begins at the sample point, is measured in TQ and is fixed at 2TQ for the Atmel CAN.
Since Phase Segment 2 also begins at the sample point and is the last segment in the bit time,
PS2 minimum shall not be less than the IPT.
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
8209D–AVR–11/10