MC9S08DZ60 Datasheet, PDF (225/396 Pages) Freescale Semiconductor, Inc – Microcontrollers

Freescale’s Controller Area Network (S08MSCANV1)
Table 12-6. CANBTR1 Register Field Descriptions (continued)
Field
Description
6:4
Time Segment 2 — Time segments within the bit time fix the number of clock cycles per bit time and the location
TSEG2[2:0] of the sample point (see Figure 12-43). Time segment 2 (TSEG2) values are programmable as shown in
Table 12-7.
3:0
Time Segment 1 — Time segments within the bit time fix the number of clock cycles per bit time and the location
TSEG1[3:0] of the sample point (see Figure 12-43). Time segment 1 (TSEG1) values are programmable as shown in
Table 12-8.
1 _{In this case, PHASE_SEG1 must be at least 2 time quanta (Tq).}
Table 12-7. Time Segment 2 Values
TSEG22
TSEG21
TSEG20
Time Segment 2
0
0
0
1 Tq clock cycle¹
0
0
1
2 Tq clock cycles
:
:
:
:
1
1
0
7 Tq clock cycles
1
1
1
8 Tq clock cycles
1 _{This setting is not valid. Please refer to Table 12-35 for valid settings.}
Table 12-8. Time Segment 1 Values
TSEG13
TSEG12
TSEG11
TSEG10
Time segment 1
0
0
0
0
1 Tq clock cycle¹
0
0
0
1
2 Tq clock cycles¹
0
0
1
0
3 Tq clock cycles¹
0
0
1
1
4 Tq clock cycles
:
:
:
:
:
1
1
1
0
15 Tq clock cycles
1
1
1
1
16 Tq clock cycles
1 _{This setting is not valid. Please refer to Table 12-35 for valid settings.}
The bit time is determined by the oscillator frequency, the baud rate prescaler, and the number of time
quanta (Tq) clock cycles per bit (as shown in Table 12-7 and Table 12-8).
Eqn. 12-1
Bit Time= ⁽---P----r---e---f-s-C--c---A-a----Nl--e--C-r----L--v--K-a----l--u----e----⁾ • (1 + TimeSegment1 + TimeSegment2)
MC9S08DZ60 Series Data Sheet, Rev. 1 Draft E
Freescale Semiconductor
PRELIMINARY
225
Subject to Change