ST72561J9-Auto STMicroelectronics, ST72561J9-Auto Datasheet - Page 230

• Manufacturer Part Number: ST72561J9-Auto
• Description: 8-bit MCU for automotive
• Manufacturer: STMicroelectronics

Specifications of ST72561J9-Auto

• Hdflash Endurance: 100 cycles, data retention 20 years at 55 °C
• 5 Power Saving Modes: halt, auto wake up from halt, active halt, wait and slow

beCAN controller (beCAN)
Note:
17.4.6
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If ABOM is set, the beCAN will start the recovering sequence automatically after it has
entered bus-off state.
If ABOM is cleared, the software must initiate the recovering sequence by requesting
beCAN to enter initialization mode. Then beCAN starts monitoring the recovery sequence
when the beCAN is requested to leave the initialization mode.
In initialization mode, beCAN does not monitor the CANRX signal, therefore it cannot
complete the recovery sequence. To recover, beCAN must be in normal mode.
Bit timing
The bit timing logic monitors the serial bus-line and performs sampling and adjustment of
the sample point by synchronizing on the start-bit edge and resynchronizing on the following
edges.
Its operation may be explained simply by splitting nominal bit time into three segments as
follows:
●
●
●
●
To guarantee the correct behavior of the CAN controller, SYNC_SEG + BS1 + BS2 must be
greater than or equal to 5 time quanta.
For a detailed description of the CAN resynchronization mechanism and other bit timing
configuration constraints, please refer to the Bosch CAN standard 2.0.
As a safeguard against programming errors, the configuration of the Bit Timing Registers
CBTR1 and CBTR0 is only possible while the device is in Initialization mode.
Figure 105. Bit timing
Synchronization segment (SYNC_SEG):
a bit change is expected to occur within this time segment. It has a fixed length of one
time quantum (1 x t
Bit segment 1 (BS1):
defines the location of the sample point. It includes the PROP_SEG and
PHASE_SEG1 of the CAN standard. Its duration is programmable between 1 and 16
time quanta but may be automatically lengthened to compensate for positive phase
drifts due to differences in the frequency of the various nodes of the network.
Bit segment 2 (BS2):
defines the location of the transmit point. It represents the PHASE_SEG2 of the CAN
standard. Its duration is programmable between 1 and 8 time quanta but may also be
automatically shortened to compensate for negative phase drifts.
Resynchronization Jump Width (RJW):
defines an upper bound to the amount of lengthening or shortening of the bit segments.
It is programmable between 1 and 4 time quanta.
SYNC_SEG
1 x t
CAN
CAN
BIT SEGMENT 1 (BS1)
).
Doc ID 12370 Rev 8
t
BS1
NOMINAL BIT TIME
SAMPLE POINT
BIT SEGMENT 2 (BS2)
t
BS2
TRANSMIT POINT
ST72561-Auto