AT91SAM7A3-AU Atmel, AT91SAM7A3-AU Datasheet - Page 503

• Manufacturer Part Number: AT91SAM7A3-AU
• Description: IC ARM7 MCU FLASH 256K 100LQFP
• Manufacturer: Atmel
• Series: AT91SAMr

Specifications of AT91SAM7A3-AU

• Core Processor: ARM7
• Core Size: 16/32-Bit
• Speed: 60MHz
• Connectivity: CAN, I²C, MMC, SPI, SSC, UART/USART
• Peripherals: POR, PWM, WDT
• Number Of I /o: 62
• Program Memory Size: 256KB (256K x 8)
• Program Memory Type: FLASH
• Ram Size: 32K x 8
• Voltage - Supply (vcc/vdd): 1.65 V ~ 1.95 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 100-LQFP
• Controller Family/series: AT91SAM7xx
• No. Of I/o's: 62
• Ram Memory Size: 32KB
• Cpu Speed: 60MHz
• No. Of Timers: 3
• Rohs Compliant: Yes
• Package: 100LQFP
• Device Core: ARM7TDMI
• Family Name: 91S
• Maximum Speed: 60 MHz
• Operating Supply Voltage: 3.3 V
• Data Bus Width: 32 Bit
• Number Of Programmable I/os: 62
• Interface Type: CAN/SPI/I2S/TWI/USART/USB
• On-chip Adc: 2(8-chx10-bit)
• Number Of Timers: 3
• Processor Series: AT91SAMx
• Core: ARM7TDMI
• Data Ram Size: 32 KB
• Maximum Clock Frequency: 60 MHz
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: JTRACE-ARM-2M, MDK-ARM, RL-ARM, ULINK2
• Development Tools By Supplier: AT91SAM-ICE, AT91-ISP, AT91SAM7A3-EK
• Minimum Operating Temperature: - 40 C
• Cpu Family: 91S
• Device Core Size: 32b
• Frequency (max): 60MHz
• Total Internal Ram Size: 32KB
• # I/os (max): 62
• Number Of Timers - General Purpose: 3
• Operating Supply Voltage (typ): 3.3V
• Operating Supply Voltage (max): 3.6V
• Operating Supply Voltage (min): 3V
• Instruction Set Architecture: RISC
• Operating Temp Range: -40C to 85C
• Operating Temperature Classification: Industrial
• Mounting: Surface Mount
• Pin Count: 100
• Package Type: LQFP
• For Use With: AT91SAM-ICE - EMULATOR FOR AT91 ARM7/ARM9AT91SAM7A3-EK - KIT EVAL FOR AT91SAM7A3
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Lead Free Status / Rohs Status: Details

6042E–ATARM–14-Dec-06
CAN Bus Synchronization
Autobaud Mode
Two types of synchronization are distinguished: “hard synchronization” at the start of a frame
and “resynchronization” inside a frame. After a hard synchronization, the bit time is restarted
with the end of the SYNC_SEG segment, regardless of the phase error. Resynchronization
causes a reduction or increase in the bit time so that the position of the sample point is shifted
with respect to the detected edge.
The effect of resynchronization is the same as that of hard synchronization when the magni-
tude of the phase error of the edge causing the resynchronization is less than or equal to the
programmed value of the resynchronization jump width (t
When the magnitude of the phase error is larger than the resynchronization jump width and
Figure 36-6. CAN Resynchronization
The autobaud feature is enabled by setting the ABM field in the CAN_MR register. In this
mode, the CAN controller is only listening to the line without acknowledging the received mes-
sages. It can not send any message. The errors flags are updated. The bit timing can be
adjusted until no error occurs (good configuration found). In this mode, the error counters are
frozen. To go back to the standard mode, the ABM bit must be cleared in the CAN_MR
register.
• the phase error is positive, then PHASE_SEG1 is lengthened by an amount equal to the
• the phase error is negative, then PHASE_SEG2 is shortened by an amount equal to the
resynchronization jump width.
resynchronization jump width.
(before resynchronization)
(before resynchronization)
resynchronization
resynchronization
Nominal bit time
Nominal bit time
Bit time with
Bit time with
Received
Received
data bit
data bit
THE PHASE ERROR IS POSITIVE
(the transmitter is slower than the receiver)
THE PHASE ERROR IS NEGATIVE
(the transmitter is faster than the receiver)
SYNC_
SYNC_
SEG
SEG
PHASE_SEG2
PHASE_
Phase error
SEG2
Phase error (max Tsjw)
Phase error
PROP_SEG
PROP_SEG
SYNC_
SEG
SYNC_
SEG
AT91SAM7A3 Preliminary
PROP_SEG
PHASE_SEG1 PHASE_SEG2
PHASE_SEG1
PROP_SEG
Sample point
Nominal
after resynchronization
Phase error (max Tsjw)
SJW
PHASE_SEG1
Sample point
).
Sample point
after resynchronization
PHASE_SEG2
PHASE_SEG1
PHASE_SEG2
SYNC_
SEG
Nominal
Sample point
PHASE_SEG2
SYNC_
SEG
SYNC_
SEG
SYNC_
SEG
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