AT90CAN128-16AE ATMEL Corporation, AT90CAN128-16AE Datasheet - Page 236

• Manufacturer Part Number: AT90CAN128-16AE
• Description: 8-bit Avr Microcontroller With 128K Bytes of Isp Flash And CAN Controller.flash (Kbytes) 128 Vcc (V) 2.7-5.5 EEPROM (Kbytes) 4 SRAM (bytes) 4K CAN (mess. Obj.) 15
• Manufacturer: ATMEL Corporation

Baud Rate
Fault Confinement
236
AT90CAN128
(
(
(
(
1
2
3
4
) Phase error
) Phase error
) Phase error
) Phase error
CLK
F
Data
CAN
IO
CLK
Figure 114. Sample and Transmission Point
Figure 115. General Structure of a Bit Period
The baud rate selection is made by T
The total number of Tscl (Time Quanta) in a bit time must be between 8 to 25.
(c.f. Section “Error Management”).
0
0
0
0
IO
Tbit = Tsyns + Tprs + Tphs1 + Tphs2
Tsyns(*)
(
*
) Synchronization Segment: SYNS
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]+ 1) x Tscl
5. Tsjw = (1 to 4) x Tscl = (SJW[1..0]+ 1) x Tscl
1
Prescaler BRP
/
CLK
Tsyns=1
IO
Tscl (TQ)
x
Tscl (
fixed
Tprs
)
Time Quantum
Fcan (Tscl)
Bit Rate Prescaler
one nominal bit
bit
Tbit
calculation:
Tphs1+Tsjw (
Tphs1 (
PHS1 (3-bit length)
PHS2 (3-bit length)
IO
PRS (3-bit length)
SJW (2-bit length)
Bit Timing
(= 1TQ)
1
)
3
Sample
)
Point
Tphs2+Tsjw (
Tphs2 (
Transmission
2
Transmission
)
4250C–CAN–03/04
Sample
4
Point
)
Point
Point