Freescale Semiconductor MC9S12ZVM series, Справочное руководство

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Chapter 12 Freescale’s Scalable Controller Area Network (S12MSCANV3)
MC9S12ZVM Family Reference Manual Rev. 1.3
Freescale Semiconductor 415
The bit time is determined by the oscillator frequency, the baud rate prescaler, and the number of time
quanta (Tq) clock cycles per bit (as shown in
Table 12-8 and Table 12-9 ).
Eqn. 12-1
12.3.2.5 MSCAN Receiver Flag Register (CANRFLG)
A flag can be cleared only by software (writing a 1 to the corresponding bit position) when the condition
which caused the setting is no longer valid. Every flag has an associated interrupt enable bit in the
CANRIER register.
Table 12-8. Time Segment 2 Values
TSEG22 TSEG21 TSEG20 Time Segment 2
0 0 0 1 Tq clock cycle
(1)
1. This setting is not valid. Please refer to Table 12-36 for valid settings.
0 0 1 2 Tq clock cycles
: : : :
1 1 0 7 Tq clock cycles
1 1 1 8 Tq clock cycles
Table 12-9. Time Segment 1 Values
TSEG13 TSEG12 TSEG11 TSEG10 Time segment 1
0 0 0 0 1 Tq clock cycle
(1)
1. This setting is not valid. Please refer to Table 12-36 for valid settings.
0 0 0 1 2 Tq clock cycles
1
0 0 1 0 3 Tq clock cycles
1
0 0 1 1 4 Tq clock cycles
: : : : :
1 1 1 0 15 Tq clock cycles
1 1 1 1 16 Tq clock cycles
Bit Time
Prescaler value
( )
f
CANCLK
------------------------------------------------------ 1 TimeSegment1 TimeSegment2 + +
( ) •
=