SAM7X256 Atmel Corporation, SAM7X256 Datasheet - Page 518

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SAM7X256

Manufacturer Part Number
SAM7X256
Description
Manufacturer
Atmel Corporation
Datasheets

Specifications of SAM7X256

Flash (kbytes)
256 Kbytes
Pin Count
100
Max. Operating Frequency
55 MHz
Cpu
ARM7TDMI
Hardware Qtouch Acquisition
No
Max I/o Pins
62
Ext Interrupts
62
Usb Transceiver
1
Usb Speed
Full Speed
Usb Interface
Device
Spi
2
Twi (i2c)
1
Uart
3
Can
1
Ssc
1
Ethernet
1
Graphic Lcd
No
Video Decoder
No
Camera Interface
No
Adc Channels
8
Adc Resolution (bits)
10
Adc Speed (ksps)
384
Resistive Touch Screen
No
Temp. Sensor
No
Crypto Engine
No
Sram (kbytes)
64
Self Program Memory
NO
Dram Memory
No
Nand Interface
No
Picopower
No
Temp. Range (deg C)
-40 to 85
I/o Supply Class
3.3
Operating Voltage (vcc)
3.0 to 3.6
Fpu
No
Mpu / Mmu
no / no
Timers
3
Output Compare Channels
3
Input Capture Channels
3
Pwm Channels
4
32khz Rtc
Yes
Calibrated Rc Oscillator
No
Figure 36-9. Disabling Low-power Mode
36.7
36.7.1
518
Functional Description
(CAN_MSRx)
SAM7X512/256/128
CAN Controller Initialization
(CAN_SR)
WAKEUP
(CAN_MR)
(CAN_SR)
CAN BUS
SLEEP
MRDY
LPM
After power-up reset, the CAN controller is disabled. The CAN controller clock must be activated
by the Power Management Controller (PMC) and the CAN controller interrupt line must be
enabled by the interrupt controller (AIC).
The CAN controller must be initialized with the CAN network parameters. The CAN_BR register
defines the sampling point in the bit time period. CAN_BR must be set before the CAN controller
is enabled by setting the CANEN field in the CAN_MR register.
The CAN controller is enabled by setting the CANEN flag in the CAN_MR register. At this stage,
the internal CAN controller state machine is reset, error counters are reset to 0, error flags are
reset to 0.
Once the CAN controller is enabled, bus synchronization is done automatically by scanning
eleven recessive bits. The WAKEUP bit in the CAN_SR register is automatically set to 1 when
the CAN controller is synchronized (WAKEUP and SLEEP are stuck at 0 after a reset).
The CAN controller can start listening to the network in Autobaud Mode. In this case, the error
counters are locked and a mailbox may be configured in Receive Mode. By scanning error flags,
the CAN_BR register values synchronized with the network. Once no error has been detected,
the application disables the Autobaud Mode, clearing the ABM field in the CAN_MR register.
Message lost
Interframe synchronization
Bus Activity Detected
Message x
6120I–ATARM–06-Apr-11

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