st92f124 STMicroelectronics, st92f124 Datasheet - Page 346

• Manufacturer Part Number: st92f124
• Description: 8/16-bit Single Voltage Flash Mcu Family With Ram, E3 Tmemulated Eeprom, Can 2.0b And J1850 Blpd
• Manufacturer: STMicroelectronics

CONTROLLER AREA NETWORK (bxCAN)
CONTROLLER AREA NETWORK (Cont’d)
CAN ERROR STATUS REGISTER (CESR)
Read / Write
Reset Value: 0000 0000 (00h)
Bit 7 = Reserved. Forced to 0 by hardware.
Bit 6:4 = LEC[2:0] Last Error Code
- Read/Set/Clear
This field holds a code which indicates the type of
the last error detected on the CAN bus. If a mes-
sage has been transferred (reception or transmis-
sion) without error, this field will be cleared to ‘0’.
The code 7 is unused and may be written by the
CPU to check for update
Table 63. LEC Error Types
Bit 3 = Reserved. Forced to 0 by hardware.
Bit 2 = BOFF Bus-Off Flag
- Read
This bit is set by hardware when it enters the bus-
off state. The bus-off state is entered on TECR
overrun, TEC greater than 255, refer to
10.10.5.6 on page
Bit 1 = EPVF Error Passive Flag
- Read
This bit is set by hardware when the Error Passive
limit has been reached (Receive Error Counter or
Transmit Error Counter greater than 127).
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9
7
0
Code
0
1
2
3
4
5
6
7
LEC2
No Error
Stuff Error
Form Error
Acknowledgment Error
Bit recessive Error
Bit dominant Error
CRC Error
Set by software
LEC1
337.
LEC0
Error Type
0
BOFF EPVF EWGF
Section
0
Bit 1 = EWGF Error Warning Flag
- Read
This bit is set by hardware when the warning limit
has been reached. Receive Error Counter or
Transmit Error Counter greater than 96.
CAN ERROR INTERRUPT ENABLE REGISTER
(CEIER)
All bits of this register are set and clear by soft-
ware.
Read/Write
Reset Value: 0000 0000 (00h)
Bit 7 = ERRIE Error Interrupt Enable
0: No interrupt will be generated when an error
1: An interrupt will be generated when an error
Bit 6:5 = Reserved. Forced to 0 by hardware.
Bit 4 = LECIE Last Error Code Interrupt Enable
0: ERRI bit will not be set when the error code in
1: ERRI bit will be set when the error code in
Bit 3 = Reserved. Forced to 0 by hardware.
Bit 2 = BOFIE Bus-Off Interrupt Enable
0: ERRI bit will not be set when BOFF is set.
1: ERRI bit will be set when BOFF is set.
Bit 1 = EPVIE Error Passive Interrupt Enable
0: ERRI bit will not be set when EPVF is set.
1: ERRI bit will be set when EPVF is set.
Bit 0 = EWGIE Error Warning Interrupt Enable
0: ERRI bit will not be set when EWGF is set.
1: ERRI bit will be set when EWGF is set.
Note: refer to Standard Interrupts Section.
ERRIE
condition is pending in the CESR.
condition is pending in the CESR.
LEC[2:0] is set by hardware on error detection.
LEC[2:0] is set by hardware on error detection.
7
0
0
LECIE
0
BOFIE EPVIE EWGIE
0