LM3S2965_0711 Datasheet, PDF (421/574 Pages) List of Unclassifed Manufacturers – Microcontroller

LM3S2965 Microcontroller
tProp 600 ns = 6 × tq
tSJW 100 ns = 1 × tq
tTSeg1 700 ns = tProp + tSJW
tTSeg2 200 ns = Information Processing Time + 1 × tq
tSync-Seg 100 ns = 1 × tq
bit time 1000 ns = tSync-Seg + tTSeg1 + tTSeg2
tolerance for CAN_CLK 0.39 % =
min(PB1,PB2)/ 2 × (13 x bit time - PB2) =
0.1us/ 2 x (13x 1us - 2us)
In the above example, the concatenated bit time parameters are (2-1)3&(7-1)4&(1-1)2&(1-1)6, and
CANBIT is programmed to 0x1600.
16.4.15.2 Example for Bit Timing at Low Baud Rate
In this example, the frequency of CAN_CLK is 2 MHz, BRP is 1, and the bit rate is 100 Kbps.
tq 1 ms = 2 × tCAN_CLK
delay of bus driver 200 ns
delay of receiver circuit 80 ns
delay of bus line (40m) 220 ns
tProp 1 ms = 1 × tq
tSJW 4 ms = 4 × tq
tTSeg1 5 ms = tProp + tSJW
tTSeg2 4 ms = Information Processing Time + 3 × tq
tSync-Seg 1 ms = 1 × tq
bit time 10 ms = tSync-Seg + tTSeg1 + tTSeg2
tolerance for CAN_CLK 1.58 % =
min(PB1,PB2)/ 2 x (13 x bit time - PB2) =
4us/ 2 x (13 x 10us - 4us)
In this example, the concatenated bit time parameters are (4-1)3&(5-1)4&(4-1)2&(2-1)6, and CANBIT
is programmed to 0x34C1.
16.5
Controller Area Network Register Map
Table 16-4 on page 421 lists the registers. All addresses given are relative to the CAN base address
of:
■ CAN0: 0x4004.0000
■ CAN1: 0x4004.1000
All accesses are on word (32-bit) boundaries.
Table 16-4. CAN Register Map
Offset Name
Type
0x000 CANCTL
R/W
0x004 CANSTS
R/W
0x008 CANERR
RO
Reset
0x0000.0001
0x0000.0000
0x0000.0000
Description
CAN Control
CAN Status
CAN Error Counter
See
page
424
426
429
November 30, 2007
421
Preliminary