LFDAS12XSFT Freescale Semiconductor, LFDAS12XSFT Datasheet - Page 306

• Manufacturer Part Number: LFDAS12XSFT
• Description: HARDWARE MC9S12XS 80-PIN
• Manufacturer: Freescale Semiconductor

Specifications of LFDAS12XSFT

• Module/board Type: *
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With/related Products: -

Freescale’s Scalable Controller Area Network (S12MSCANV3)
11.3.2.4
The CANBTR1 register configures various CAN bus timing parameters of the MSCAN module.
1. Read: Anytime
1. In this case, PHASE_SEG1 must be at least 2 time quanta (Tq).
306
Module Base + 0x0003
TSEG2[2:0]
TSEG1[3:0]
Write: Anytime in initialization mode (INITRQ = 1 and INITAK = 1)
SAMP
Field
6-4
3-0
7
Reset:
W
R
Sampling — This bit determines the number of CAN bus samples taken per bit time.
0 One sample per bit.
1 Three samples per bit
If SAMP = 0, the resulting bit value is equal to the value of the single bit positioned at the sample point. If
SAMP = 1, the resulting bit value is determined by using majority rule on the three total samples. For higher bit
rates, it is recommended that only one sample is taken per bit time (SAMP = 0).
Time Segment 2 — Time segments within the bit time fix the number of clock cycles per bit time and the location
of the sample point (see
Table
Time Segment 1 — Time segments within the bit time fix the number of clock cycles per bit time and the location
of the sample point (see
Table
MSCAN Bus Timing Register 1 (CANBTR1)
SAMP
0
7
11-9.
11-10.
BRP5
0
0
0
0
1
:
Figure 11-7. MSCAN Bus Timing Register 1 (CANBTR1)
TSEG22
BRP4
0
0
0
0
1
Table 11-8. CANBTR1 Register Field Descriptions
:
6
0
(1)
Figure
Figure
S12XS Family Reference Manual, Rev. 1.11
BRP3
.
0
0
0
0
1
:
Table 11-7. Baud Rate Prescaler
TSEG21
11-44). Time segment 2 (TSEG2) values are programmable as shown in
11-44). Time segment 1 (TSEG1) values are programmable as shown in
0
5
BRP2
0
0
0
0
1
:
TSEG20
BRP1
4
0
0
0
1
1
1
:
Description
BRP0
TSEG13
0
1
0
1
1
:
0
3
TSEG12
Prescaler value (P)
2
0
64
1
2
3
4
:
Access: User read/write
TSEG11
Freescale Semiconductor
0
1
TSEG10
0
0
(1)