66.6.6 MCAN Nominal Bit Timing and Prescaler Register

This register can only be written if the bits CCE and INIT are set in MCAN_CCCR.

The CAN bit time may be programmed in the range of 4 to 385 time quanta. The CAN time quantum may be programmed in the range of 1 to 512 CAN core clock periods. t_q = t_{core clock}x (NBRP + 1).

NTSEG1 is the sum of Prop_Seg and Phase_Seg1. NTSEG2 is Phase_Seg2.

Therefore the length of the bit time is (programmed values) [NTSEG1 + NTSEG2 + 3] t_qor (functional values) [Sync_Seg + Prop_Seg + Phase_Seg1 + Phase_Seg2] t_q.

The Information Processing Time (IPT) is zero, meaning the data for the next bit is available at the first clock edge after the sample point.

With a CAN core clock frequency of 8 MHz, the reset value of 0x06000A03 configures the MCAN for a bit rate of 500 kbit/s.

Name:	MCAN_NBTP
Offset:	0x1C
Reset:	0x06000A03
Property:	Read/Write


Bit	31	30	29	28	27	26	25	24
	NSJW[6:0]							NBRP[8]
Access	R/W	R/W	R/W	R/W	R/W	R/W	R/W	R/W
Reset	0	0	0	0	0	1	1	0


Bit	23	22	21	20	19	18	17	16
	NBRP[7:0]
Access	R/W	R/W	R/W	R/W	R/W	R/W	R/W	R/W
Reset	0	0	0	0	0	0	0	0


Bit	15	14	13	12	11	10	9	8
	NTSEG1[7:0]
Access	R/W	R/W	R/W	R/W	R/W	R/W	R/W	R/W
Reset	0	0	0	0	1	0	1	0


Bit	7	6	5	4	3	2	1	0
		NTSEG2[6:0]
Access		R/W	R/W	R/W	R/W	R/W	R/W	R/W
Reset		0	0	0	0	0	1	1

Bits 31:25 – NSJW[6:0] Nominal (Re) Synchronization Jump Width

0 to 127: The duration of a synchronization jump is t_qx (NSJW + 1).

Bits 24:16 – NBRP[8:0] Nominal Bit Rate Prescaler

0 to 511: The value by which the oscillator frequency is divided for generating the CAN time quanta. The CAN time is built up from a multiple of this quanta. CAN time quantum (tq) = t_{core clock}x (NBRP + 1)

Bits 15:8 – NTSEG1[7:0] Nominal Time Segment Before Sample Point

Value	Description
0	Reserved; do not use.
1 to 255	The duration of time segment is t_qx (NTSEG1 + 1).

Bits 6:0 – NTSEG2[6:0] Nominal Time Segment After Sample Point

Value	Description
0	Reserved; do not use.
1 to 127	The duration of time segment is t_qx (NTSEG2 + 1).