Texas Instruments TMS320x281 series, Справочное руководство

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3.1.4 Bit Configuration Parameters for 100-MHz CAN Clock
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CAN Module Initialization
Table 3-4 shows how the BRP
reg
field may be changed to achieve different bit rates with a BT of 10 for an
80% SP.
Table 3-4. BRP Field for Bit Rates (BT = 10, TSEG1
reg
= 6, TSEG2
reg
= 1, Sampling Point = 80%)
CAN Bus Speed BRP CAN Module Clock
1 Mbps BRP
reg
+1 = 10 10 MHz
500 kbps BRP
reg
+1 = 20 5 MHz
250 kbps BRP
reg
+1 = 40 2.5 MHz
125 kbps BRP
reg
+1 = 80 1.25 MHz
100 kbps BRP
reg
+1 = 100 1 MHz
50 kbps BRP
reg
+1 = 200 0.5 MHz
Table 3-5 shows how to achieve different sampling points with a BT of 20.
Table 3-5. Achieving Different Sampling Points With a BT of 20
TSEG1
reg
TSEG2
reg
SP
15 2 85%
14 3 80%
13 4 75%
12 5 70%
11 6 65%
10 7 60%
Table 3-6 shows how BRP
reg
field may be changed to achieve different bit rates with a BT of 20 for the
sampling points shown in Table 3-5 .
Table 3-6. BRP Field for Bit Rates
CAN Bus Speed BRP
1 Mbps BRP
reg
+1 = 5
500 kbps BRP
reg
+1 =10
250 kbps BRP
reg
+1 = 20
125 kbps BRP
reg
+1 = 40
100 kbps BRP
reg
+1 = 50
50 kbps BRP
reg
+1 = 100
Note: For a SYSCLKOUT of 150 MHz, the lowest bit-rate that can be achieved is 23.437 kbps.
For a SYSCLKOUT of 100 MHz, the lowest bit-rate that can be achieved is 15.625 kbps.
For a SYSCLKOUT of 60 MHz, the lowest bit-rate that can be achieved is 9.375 kbps.
SPRU074F – May 2002 – Revised January 2009 eCAN Configuration 71
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