RM0090: Reference manual - STMicroelectronics

RM0090 Controller area network (bxCAN)
Figure 224. Dual CAN block diagram
Control/Status/Configuration
Control/Status/Configuration
Master Control
Master Status
Tx Status
Rx FIFO 0 St at us
Rx FIFO 1 St at us
Interrupt Enable
Error Status
Bit Timing
Filter Master
Filter Mode
Filter Scale
Filter FIFO Assign
Filter Activation
Master Control
Master Status
Tx Status
Rx FIFO 0 St at us
Rx FIFO 1 St at us
Interrupt Enable
Error Status
Bit Timing
CAN2 (Slave)
CAN 2.0B Active Core
CAN 2.0B Active Core
24.4 bxCAN operating modes
CAN1 (Master) with 512 bytes SRAM
Master
Tx Mailboxes
2
1
Mailbox 0
Transmission
Scheduler
Memory
Access
Controller
Transmission
Scheduler
Slave
Tx Mailboxes
2
1
Mailbox 0
Acceptance Filters
bxCAN has three main operating modes: initialization, normal and Sleep. After a
hardware reset, bxCAN is in Sleep mode to reduce power consumption and an internal pullup
is active on CANTX. The software requests bxCAN to enter initialization or Sleep mode
by setting the INRQ or SLEEP bits in the CAN_MCR register. Once the mode has been
entered, bxCAN confirms it by setting the INAK or SLAK bits in the CAN_MSR register and
the internal pull-up is disabled. When neither INAK nor SLAK are set, bxCAN is in normal
Filter
Master
Receive FIFO 0
2
1
Mailbox 0
..
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Doc ID 018909 Rev 3 662/1416
0
1
Master Filters
(0 to 27)
2
3
Master
Receive FIFO 1
2
1
Mailbox 0
Slave
Receive FIFO 0
Slave
Receive FIFO 1
2
2
Mailbox 0
1
Mailbox 0
1
..
Slave Filters
(0 to 27)
Note: CAN 2 start filter bank number n is confi gurable by writing to
the CAN2SB[5:0] bits in the CAN_ FMR register.
27
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