AT90CAN32 Automotive Atmel Corporation, AT90CAN32 Automotive Datasheet - Page 241

• 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

19.4.3
7682C–AUTO–04/08
Notes:
Baud Rate
5.
2.
3.
4.
1.
Phase error > 0
Phase error > 0
Phase error < 0
Synchronization Segment: SYNS
Tsyns=1
Phase error < 0
x
Tscl (
The total number of TQ in a bit time has to be programmed at least from 8 to 25.
Figure 19-7. Sample and Transmission Point
Figure 19-8. General Structure of a Bit Period
With no baud rate prescaler (BRP[5..0]=0) the sampling point comes one time quantum too
early. This leads to a fail according the ISO16845 Test plan. It is necessary to lengthen the
Phase Segment 1 by one time quantum and to shorten the Phase Segment 2 by one time quan-
tum to compensate.
The baud rate selection is made by T
CLK
1. Tsyns = 1 x Tscl = (BRP[5..0]+ 1)/clk
2. Tprs = (1 to 8) x Tscl = (PRS[2..0]+ 1) x Tscl
3. Tphs1 = (1 to 8) x Tscl = (PHS1[2..0]+ 1) x Tscl
4. Tphs2 = (1 to 8) x Tscl = (PHS2[2..0]
F
Data
CAN
fixed
IO
CLK
)
IO
Tbit
Tsyns(5)
(1)
= Tsyns + Tprs + Tphs1 + Tphs2
1
Prescaler BRP
/
CLK
IO
Tscl (TQ)
Tprs
bit
Time Quantum
calculation:
Fcan (Tscl)
Bit Rate Prescaler
IO
one nominal bit
(2)
+ 1) x Tscl
(= 1TQ)
Tbit
Tphs1+Tsjw
Tphs1
PHS1 (3-bit length)
PHS2 (3-bit length)
PRS (3-bit length)
SJW (2-bit length)
Bit Timing
or
AT90CAN32/64/128
(
1
)
Sample
(
Point
3
)
Tphs2+Tsjw
Tphs2
or
Transmission
(
Transmission
2
Sample
)
Point
(
Point
Point
4
)
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