SAM7X256 Atmel Corporation, SAM7X256 Datasheet - Page 546

• Manufacturer Part Number: SAM7X256
• Manufacturer: Atmel Corporation

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

36.8.9
Name:
Access Type:
• REC: Receive Error Counter
When a receiver detects an error, REC will be increased by one, except when the detected error is a BIT ERROR while
sending an ACTIVE ERROR FLAG or an OVERLOAD FLAG.
When a receiver detects a dominant bit as the first bit after sending an ERROR FLAG, REC is increased by 8.
When a receiver detects a BIT ERROR while sending an ACTIVE ERROR FLAG, REC is increased by 8.
Any node tolerates up to 7 consecutive dominant bits after sending an ACTIVE ERROR FLAG, PASSIVE ERROR FLAG or
OVERLOAD FLAG. After detecting the 14th consecutive dominant bit (in case of an ACTIVE ERROR FLAG or an OVER-
LOAD FLAG) or after detecting the 8th consecutive dominant bit following a PASSIVE ERROR FLAG, and after each
sequence of additional eight consecutive dominant bits, each receiver increases its REC by 8.
After successful reception of a message, REC is decreased by 1 if it was between 1 and 127. If REC was 0, it stays 0, and
if it was greater than 127, then it is set to a value between 119 and 127.
• TEC: Transmit Error Counter
When a transmitter sends an ERROR FLAG, TEC is increased by 8 except when
When a transmitter detects a BIT ERROR while sending an ACTIVE ERROR FLAG or an OVERLOAD FLAG, the TEC will
be increased by 8.
Any node tolerates up to 7 consecutive dominant bits after sending an ACTIVE ERROR FLAG, PASSIVE ERROR FLAG or
OVERLOAD FLAG. After detecting the 14th consecutive dominant bit (in case of an ACTIVE ERROR FLAG or an OVER-
LOAD FLAG) or after detecting the 8th consecutive dominant bit following a PASSIVE ERROR FLAG, and after each
sequence of additional eight consecutive dominant bits every transmitter increases its TEC by 8.
After a successful transmission the TEC is decreased by 1 unless it was already 0.
546
– the transmitter is error passive and detects an ACKNOWLEDGMENT ERROR because of not detecting a
– the transmitter sends an ERROR FLAG because a STUFF ERROR occurred during arbitration and should
31
23
15
–
–
7
dominant ACK and does not detect a dominant bit while sending its PASSIVE ERROR FLAG.
have been recessive and has been sent as recessive but monitored as dominant.
SAM7X512/256/128
CAN Error Counter Register
30
22
14
CAN_ECR
Read-only
–
–
6
29
21
13
–
–
5
28
20
12
–
–
4
REC
TEC
27
19
11
–
–
3
26
18
10
–
–
2
25
17
–
9
–
1
6120I–ATARM–06-Apr-11
24
16
–
8
–
0