ST STM32F412 Reference Manual page 953

RM0402
This register also implements the TX request control (bit 0) - reset value 0.
31 30 29
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15 14 13
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Bits 31:21 STID[10:0]/EXID[28:18]
Bit 20:3 EXID[17:0]: Extended identifier
Bit 2 IDE
Bit 1 RTR
Bit 0 TXRQ
28 27 26 25
STID[10:0]/EXID[28:18]
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12 11 10 9
EXID[12:0]
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:
Standard identifier or extended identifier
The standard identifier or the MSBs of the extended identifier (depending on the IDE bit
value).
The LSBs of the extended identifier.
:
Identifier extension
This bit defines the identifier type of message in the mailbox.
0: Standard identifier.
1: Extended identifier.
:
Remote transmission request
0: Data frame
1: Remote frame
:
Transmit mailbox request
Set by software to request the transmission for the corresponding mailbox.
Cleared by hardware when the mailbox becomes empty.
24 23 22
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8 7 6
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RM0402 Rev 6
Controller area network (bxCAN)
21 20 19 18
EXID[17:13]
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5 4 3 2
IDE
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17 16
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1 0
RTR TXRQ
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