Datasheet

• R2 Bits 31:24 - DB3[7:0]: Data Byte 3
• R2 Bits 23:16 - DB2[7:0]: Data Byte 2
• R2 Bits 15:8 - DB1[7:0]: Data Byte 1
• R2 Bits 7:0 - DB0[7:0]: Data Byte 0
• R3 Bits 31:24 - DB7[7:0]: Data Byte 7
• R3 Bits 23:16 - DB6[7:0]: Data Byte 6
• R3 Bits 15:8 - DB5[7:0]: Data Byte 5
• R3 Bits 7:0 - DB4[7:0]: Data Byte 4
...
• Rn Bits 31:24 - DBm[7:0]: Data Byte m
• Rn Bits 23:16 - DBm-1[7:0]: Data Byte m-1
• Rn Bits 15:8 - DBm-2[7:0]: Data Byte m-2
• Rn Bits 7:0 - DBm-3[7:0]: Data Byte m-3
WARNING
Depending on the configuration of RXESC, between two and sixteen 32-bit words (Rn = 3 ... 17)
are used for storage of a CAN message’s data field.
39.9.3 Tx Buffer Element
The Tx Buffers section can be configured to hold dedicated Tx Buffers as well as a Tx FIFO / Tx Queue.
In case that the Tx Buffers section is shared by dedicated Tx buffers and a Tx FIFO / Tx Queue, the
dedicated Tx Buffers start at the beginning of the Tx Buffers section followed by the buffers assigned to
the Tx FIFO or Tx Queue. The Tx Handler distinguishes between dedicated Tx Buffers and Tx FIFO / Tx
Queue by evaluating the Tx Buffer configuration TXBC.TFQS and TXBC.NDTB. The element size can be
configured for storage of CAN FD messages with up to 64 bytes data field via register TXESC.
Table 39-9. Tx Buffer Element
31 3
0
29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
T0
E
S
I
X
T
D
R
T
R
ID[28:0]
T1 MM[7:0]
E
F
C
F
D
F
B
R
S
DLC[3:0]
T2 DB3[7:0] DB2[7:0] DB1[7:0] DB0[7:0]
T3 DB7[7:0] DB6[7:0] DB5[7:0] DB4[7:0]
... ... ... ... ...
Tn DBm[7:0] DBm-1[7:0] DBm-2[7:0] DBm-3[7:0]
• T0 Bit 31 - ESI: Error State Indicator
0 : ESI bit in CAN FD format depends only on error passive flag.
1 : ESI bit in CAN FD format transmitted recessive.
SAM D5x/E5x Family Data Sheet
CAN - Control Area Network
© 2019 Microchip Technology Inc.
Datasheet
DS60001507E-page 1304