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Chapter 18
AFCAN Controller
User’s Manual U16580EE3V1UD00
18.3.7 Baud rate control function
(1)
Prescaler
The CAN controller has a prescaler that divides the clock (f
CAN
) supplied to CAN. This prescaler
generates a CAN protocol layer basic system clock (f
TQ
) derived from the CAN module system
clock (f
CANMOD
), and divided by 1 to 256 (“CnBRP - CANn module bit rate prescaler register” on
(2)
Data bit time (8 to 25 time quanta)
One data bit time is defined as shown in Figure 18-18:
The CAN Controller sets time segment 1, time segment 2, and re-Synchronization Jump Width
(SJW) of data bit time, as shown in Figure
. Time segment 1 is equivalent to the total of the
propagation (prop) segment and phase segment 1 that are defined by the CAN protocol specifica-
tion. Time segment 2 is equivalent to phase segment 2.
Figure 18-18:
Segment setting
Notes: 1.
IPT: Information Processing Time
2.
TQ: Time Quanta
Reference: The CAN protocol specification defines the segments constituting the data bit time as
shown in Figure18-19.
Table 18-15:
Segment setting
Segment name
Settable range
Notes on setting to conform to CAN specification
Time segment 1 (TSEG1)
2TQ to 15TQ
-
Time segment 2 (TSEG2)
1TQ to 8TQ
IPT of the CAN controller is 0TQ. To conform to the
CAN protocol specification, therefore, a length less
or equal to phase segment 1 must be set here.
This means that the length of time segment 1
minus 1TQ is the settable upper limit of time
segment 2.
Re-synchronization Jump
Width (SJW)
1TQ to 4TQ
The length of time segment 1 minus 1TQ or 4 TQ,
whichever is smaller.
Data bit time(DBT)
Phase segment 1
Prop segment
Sync segment
Phase segment 2
Time segment 1(TSEG1)
Time segment 2
(TSEG2)
Sample point (SPT)
Summary of Contents for MuPD70F3187
Page 6: ...6 Preface User s Manual U16580EE3V1UD00 ...
Page 16: ...16 User s Manual U16580EE3V1UD00 ...
Page 28: ...28 User s Manual U16580EE3V1UD00 ...
Page 32: ...32 User s Manual U16580EE3V1UD00 ...
Page 84: ...84 Chapter 2 Pin Functions User s Manual U16580EE3V1UD00 MEMO ...
Page 144: ...144 Chapter 3 CPU Functions User s Manual U16580EE3V1UD00 MEMO ...
Page 312: ...312 Chapter 9 16 Bit Timer Event Counter P User s Manual U16580EE3V1UD00 MEMO ...
Page 534: ...534 Chapter 11 16 bit Timer Event Counter T User s Manual U16580EE3V1UD00 ...
Page 969: ...969 Chapter 20 Port Functions User s Manual U16580EE3V1UD00 MEMO ...
Page 970: ...970 Chapter 20 Port Functions User s Manual U16580EE3V1UD00 ...
Page 976: ...976 Chapter 22 Internal RAM Parity Check Function User s Manual U16580EE3V1UD00 MEMO ...
Page 984: ...984 Chapter 23 On Chip Debug Function OCD User s Manual U16580EE3V1UD00 MEMO ...
Page 1006: ...1006 Chapter 24 Flash Memory User s Manual U16580EE3V1UD00 MEMO ...
Page 1036: ...1036 Chapter 27 Recommended Soldering Conditions User s Manual U16580EE3V1UD00 MEMO ...
Page 1046: ...1046 Appendix A Index User s Manual U16580EE3V1UD00 MEMO ...
Page 1052: ...1052 User s Manual U16580EE3V1UD00 ...
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