MPC563XM Reference Manual, Rev. 1
1290
Freescale Semiconductor
Preliminary—Subject to Change Without Notice
•
If the value of Tx_Err_Counter or Rx_Err_Counter increases to be greater than or equal to 128, the
FLT_CONF field in the Error and Status Register is updated to reflect ‘Error Passive’ state.
•
If the FlexCAN state is ‘Error Passive’, and either Tx_Err_Counter or Rx_Err_Counter decrements
to a value less than or equal to 127 while the other already satisfies this condition, the FLT_CONF
field in the Error and Status Register is updated to reflect ‘Error Active’ state.
•
If the value of Tx_Err_Counter increases to be greater than 255, the FLT_CONF field in the Error
and Status Register is updated to reflect ‘Bus Off’ state, and an interrupt may be issued. The value
of Tx_Err_Counter is then reset to zero.
•
If FlexCAN is in ‘Bus Off’ state, then Tx_Err_Counter is cascaded together with another internal
counter to count the 128th occurrences of 11 consecutive recessive bits on the bus. Hence,
Tx_Err_Counter is reset to zero and counts in a manner where the internal counter counts 11 such
bits and then wraps around while incrementing the Tx_Err_Counter. When Tx_Err_Counter
reaches the value of 128, the FLT_CONF field in the Error and Status Register is updated to be
‘Error Active’ and both error counters are reset to zero. At any instance of dominant bit following
a stream of less than 11 consecutive recessive bits, the internal counter resets itself to zero without
affecting the Tx_Err_Counter value.
•
If during system start-up, only one node is operating, then its Tx_Err_Counter increases in each
message it is trying to transmit, as a result of acknowledge errors (indicated by the ACK_ERR bit
in the Error and Status Register). After the transition to ‘Error Passive’ state, the Tx_Err_Counter
does not increment anymore by acknowledge errors. Therefore the device never goes to the ‘Bus
Off’ state.
•
If the Rx_Err_Counter increases to a value greater than 127, it is not incremented further, even if
more errors are detected while being a receiver. At the next successful message reception, the
counter is set to a value between 119 and 127 to resume to ‘Error Active’ state.
Figure 28-9. Error Counter Register (ECR)
28.4.4.8
Error and Status Register (ESR)
This register reflects various error conditions, some general status of the device and it is the source of four
interrupts to the CPU. The reported error conditions (bits 16-21) are those that occurred since the last time
the CPU read this register. The CPU read action clears bits 16-21. Bits 22-28 are status bits.
Base + $001C
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
R
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
W
RESET:
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
R
Rx_Err_Counter
Tx_Err_Counter
W
RESET:
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
= Unimplemented or Reserved
Содержание MPC5632M
Страница 22: ...MPC563XM Reference Manual Rev 1 22 Freescale Semiconductor Preliminary Subject to Change Without Notice ...
Страница 62: ...MPC563XM Reference Manual Rev 1 62 Freescale Semiconductor Preliminary Subject to Change Without Notice ...
Страница 92: ...MPC563XM Reference Manual Rev 1 92 Freescale Semiconductor Preliminary Subject to Change Without Notice ...
Страница 168: ...MPC563XM Reference Manual Rev 1 168 Freescale Semiconductor Preliminary Subject to Change Without Notice ...
Страница 242: ...MPC563XM Reference Manual Rev 1 242 Freescale Semiconductor Preliminary Subject to Change Without Notice ...
Страница 302: ...MPC563XM Reference Manual Rev 1 302 Freescale Semiconductor Preliminary Subject to Change Without Notice ...
Страница 410: ...MPC563XM Reference Manual Rev 1 410 Freescale Semiconductor Preliminary Subject to Change Without Notice ...
Страница 440: ...MPC563XM Reference Manual Rev 1 440 Freescale Semiconductor Preliminary Subject to Change Without Notice ...
Страница 464: ...MPC563XM Reference Manual Rev 1 464 Freescale Semiconductor Preliminary Subject to Change Without Notice ...
Страница 554: ...MPC563XM Reference Manual Rev 1 554 Freescale Semiconductor Preliminary Subject to Change Without Notice ...
Страница 590: ...MPC563XM Reference Manual Rev 1 590 Freescale Semiconductor Preliminary Subject to Change Without Notice ...
Страница 622: ...MPC563XM Reference Manual Rev 1 622 Freescale Semiconductor Preliminary Subject to Change Without Notice ...
Страница 716: ...MPC563XM Reference Manual Rev 1 716 Freescale Semiconductor Preliminary Subject to Change Without Notice ...
Страница 1114: ...MPC563XM Reference Manual Rev 1 1114 Freescale Semiconductor Preliminary Subject to Change Without Notice ...
Страница 1144: ...MPC563XM Reference Manual Rev 1 1144 Freescale Semiconductor Preliminary Subject to Change Without Notice ...
Страница 1266: ...MPC563XM Reference Manual Rev 1 1266 Freescale Semiconductor Preliminary Subject to Change Without Notice ...
Страница 1316: ...MPC563XM Reference Manual Rev 1 1316 Freescale Semiconductor Preliminary Subject to Change Without Notice ...
Страница 1348: ...MPC563XM Reference Manual Rev 1 1348 Freescale Semiconductor Preliminary Subject to Change Without Notice ...
Страница 1362: ...MPC563XM Reference Manual Rev 1 1362 Freescale Semiconductor Preliminary Subject to Change Without Notice ...
Страница 1382: ...MPC563XM Reference Manual Rev 1 1382 Freescale Semiconductor Preliminary Subject to Change Without Notice ...