754
Chapter 18
AFCAN Controller
User’s Manual U16580EE3V1UD00
(2)
Output timing of error frame
(3)
Processing in case of error
The transmission node re-transmits the data frame or remote frame after the error frame. (How-
ever, it does not re-transmit the frame in the single-shot mode.)
(4)
Error state
(a) Types of error states
The following three types of error states are defined by the CAN specification:
•
Error active
•
Error passive
•
Bus-off
These types of error states are classified by the values of the TEC7 to TEC0 bits (transmission
error counter bits) and the REC6 to REC0 bits (reception error counter bits) as shown in
Table 18-13, “Types of error states,” on page 755.
The present error state is indicated by the CAN module information register (CnINFO).
When each error counter value becomes equal to or greater than the error warning level (96), the
TECS0 or RECS0 bit of the CnINFO register is set to 1. In this case, the bus state must be tested
because it is considered that the bus has a serious fault. An error counter value of 128 or more
indicates an error passive state and the TECS1 or RECS1 bit of the CnINFO register is set to 1.
•
If the value of the transmission error counter is greater than or equal to 256 (actually, the
transmission error counter does not indicate a value greater than or equal to 256), the bus-off
state is reached and the BOFF bit of the CnINFO register is set to 1.
•
If only one node is active on the bus at startup (i.e., a particular case such as when the bus is
connected only to the local station), ACK is not returned even if data is transmitted.
Consequently, re-transmission of the error frame and data is repeated. In the error passive
state, however, the transmission error counter is not incremented and the bus-off state is not
reached.
Table 18-12:
Output timing of error frame
Type
Output Timing
Bit error, stuff error,
form error, ACK error
Error frame output is started at the timing of the bit following
the detected error.
CEC error
Error frame output is started at the timing of the bit following
the ACK delimiter.
Содержание MuPD70F3187
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Страница 192: ...192 Chapter 5 Memory Access Control Function μPD70F3187 only User s Manual U16580EE3V1UD00 MEMO ...
Страница 312: ...312 Chapter 9 16 Bit Timer Event Counter P User s Manual U16580EE3V1UD00 MEMO ...
Страница 534: ...534 Chapter 11 16 bit Timer Event Counter T User s Manual U16580EE3V1UD00 ...
Страница 969: ...969 Chapter 20 Port Functions User s Manual U16580EE3V1UD00 MEMO ...
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Страница 976: ...976 Chapter 22 Internal RAM Parity Check Function User s Manual U16580EE3V1UD00 MEMO ...
Страница 984: ...984 Chapter 23 On Chip Debug Function OCD User s Manual U16580EE3V1UD00 MEMO ...
Страница 1006: ...1006 Chapter 24 Flash Memory User s Manual U16580EE3V1UD00 MEMO ...
Страница 1036: ...1036 Chapter 27 Recommended Soldering Conditions User s Manual U16580EE3V1UD00 MEMO ...
Страница 1046: ...1046 Appendix A Index User s Manual U16580EE3V1UD00 MEMO ...
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