Flexcan Control Register 2 (Canctrl2); Presdiv Field Descriptions; Canctrl2 Field Descriptions - Motorola ColdFire MCF5281 User Manual

Bits Name
7–0 PRES_DIV Prescaler divide factor. PRESDIV determines the ratio between the system clock frequency and
the serial clock (S-clock). The S-clock is determined by the following calculation:
The reset value of PRESDIV is 0x00, which forces the S-clock to default to the same frequency
as the system clock. The valid programmed values are 0 through 255. See Section 25.4.8, "Bit
Timing" for more information.

25.5.5 FlexCAN Control Register 2 (CANCTRL2)

7
Field RJW
Reset
R/W
Address
Figure 25-10. FlexCAN Control Register 2 (CANCTRL2)
Table 25-13 describes the CANCTRL2 fields.
Bits Name
7–6 RJW Resynchronization jump width. The RJW field defines the maximum number of time quanta a bit time
may be changed during resynchronization. The valid programmed values are 0 through 3.
The resynchronization jump width is calculated as follows:
Resynchronizaton Jump Width = (RJW + 1) Time Quanta
5–3 PSEG1 PSEG1[2:0] — Phase buffer segment 1. The PSEG1 field defines the length of phase buffer segment
1 in the bit time. The valid programmed values are 0 through 7.
The length of phase buffer segment 1 is calculated as follows:
Phase Buffer Segment 1 = (PSEG1 + 1) Time Quanta
2–0 PSEG2 PSEG2 — Phase Buffer Segment 2. The PSEG2 field defines the length of phase buffer segment 2 in
the bit time. The valid programmed values are 0 through 7.
The length of phase buffer segment 2 is calculated as follows:
Phase Buffer Segment 2 = (PSEG2 + 1) Time Quanta
MOTOROLA
Table 25-12. PRESDIV Field Descriptions
6 5
IPSBAR + 0x1C_0009
Table 25-13. CANCTRL2 Field Descriptions
Chapter 25. FlexCAN
Description
f sys
S-clock = -------------------------------------------- -
(
2 PRESDIV + 1
3
PSEG1
0000_0000
R/W
Description
Programmer's Model
)
2
PSEG2
0
25-25