AT90CAN128-16AE ATMEL Corporation, AT90CAN128-16AE Datasheet - Page 252

• 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

CAN Bit Timing Register 3 -
CANBT3
CAN Timer Control Register -
CANTCON
252
AT90CAN128
• Bit 3:1 – PRS2:0: Propagation Time Segment
This part of the bit time is used to compensate for the physical delay times within the
network. It is twice the sum of the signal propagation time on the bus line, the input com-
parator delay and the output driver delay.
• Bit 0 – Reserved Bit
This bit is reserved for future use. For compatibility with future devices, this must be writ-
ten to zero when CANBT2 is written.
• Bit 7– Reserved Bit
This bit is reserved for future use. For compatibility with future devices, this must be writ-
ten to zero when CANBT3 is written.
• Bit 6:4 – PHS22:0: Phase Segment 2
This phase is used to compensate for phase edge errors. This segment may be short-
ened by the re-synchronization jump width.
• Bit 3:1 – PHS12:0: Phase Segment 1
This phase is used to compensate for phase edge errors. This segment may be length-
ened by the re-synchronization jump width.
• Bit 0 – SMP: Sample Point(s)
• Bit 7:0 – TPRSC7:0: CAN Timer Prescaler
Prescaler for the CAN timer upper counter range 0 to 255. It provides the clock to the
CAN timer if the CAN controller is enabled.
Bit
Read/Write
Initial Value
Bit
Read/Write
Initial Value
–
–
0 - once, at the sample point.
1 - three times, the threefold sampling of the bus is the sample point and twice
over a distance of a 1/2 period of the Tscl. The result corresponds to the
majority decision of the three values.
TPRSC7
R/W
7
7
0
-
-
-
CLK
TPRSC6
PHS22
R/W
R/W
6
0
6
0
CANTIM
Tphs2 = Tscl x (PHS2 [2:0] + 1)
Tphs1 = Tscl x (PHS1 [2:0] + 1)
TPRSC5
Tprs = Tscl x (PRS [2:0] + 1)
PHS21
R/W
R/W
= CLK
5
0
5
0
IO
TPRSC4
PHS20
R/W
R/W
x 8 x (CANTCON [7:0] + 1)
4
0
4
0
TPRSC3
PHS12
R/W
R/W
3
0
3
0
TPRSC2
PHS11
R/W
R/W
2
0
2
0
TRPSC1
PHS10
R/W
R/W
1
0
1
0
TPRSC0
SMP
R/W
R/W
0
0
0
0
4250C–CAN–03/04
CANTCON
CANBT3