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GD32F403xx User Manual
605
FIFOs, the RX pin is disconnected f rom the CAN network and the TX pin can still send
messages to the CAN network.
Setting LCMOD bit in CAN_BT register to enter loopback communication mode, while clearing
it to leave. Loopback communication mode is useful for self-test.
Loopback and silent communication mode
Loopback and silent communication mode means the RX and TX pins are disconnected from
the CAN network while the transmitted messages are transferred into the Rx FIFOs.
Setting LCMOD and SCMOD bit in CAN_BT register to enter loopback and silent
communication mode, while clearing them to leave.
Loopback and silent communication mode is used for self-test. The TX pin holds in recessive
state. The RX pin holds in high impedance state.
Normal communication mode
Normal communication mode is the def ault communication mode when the LCMOD and
SCMOD bits in CAN_BT register are cleared.
22.3.3.
Data transmission
Transmission register
Three transmit mailboxes are used f or the application. Transmit mailboxes are used by
conf iguring f our transmission registers: CAN_TMIx, CAN_TMPx, CAN_TMDATA0x and
CAN_TMDATA1x. As is shown in
Figure 22-2. Transmission register
.
Figure 22-2. Transmission register
Application
Transmit
mailbox 0
Transmit
mailbox 1
Transmit
mailbox 2
TMI2
TMP2
TMDATA02
TMDATA12
TMI0
TMP0
TMDATA00
TMDATA10
TMI1
TMP1
TMDATA01
TMDATA11