8.6.5.7.4 Tx Event FIFO Element
Each element stores information about transmitted messages. By reading the Tx Event FIFO the processor gets this information in the order the messages were transmitted. Status information about the Tx Event FIFO can be obtained from register TXEFS.
E1A: When CCCR.WMM = ‘0’ and no TSU is used (CCCR.UTSU = ‘0’), E1A.TXTS[15:0] holds the 16-bit timestamp generated by the MCAN internal timestamping logic.
E1B: When 16-bit Message Markers are enabled (CCCR.WMM =’1’) or when CCCR.UTSU = ‘1’, E1B.MM[15:8] holds the upper 8 bit of the Wide Message Marker. When a TSU is used (CCCR.UTSU = ‘1’) and when bit TSCE of the related Tx Buffer element is set, E1B.TSC = ‘1’ and E1B.TXTSP[3:0] holds the number of the TSU Timestamp register which holds the 32-bit timestamp captured by the TSU. Else E1B.TSC = ‘0’ and E1B.TXTSP[3:0] is not valid.
| 31 | 30 | 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 | ||
| E0 | ESI | XTD | RTR | ID[28:0] | |||||||||||||||||||||||||||||
| E1A | MM[7:0] | ET[1:0] | FDF | BRS | DLC[3:0] | TXTS[15:0] | |||||||||||||||||||||||||||
| E1B | MM[7:0] | ET[1:0] | FDF | BRS | DLC[3:0] | MM[15:8] | – | TSC | TXTSP[3:0] | ||||||||||||||||||||||||
• E0 Bit 31 ESI: Error State Indicator
0: Transmitting node is error active.
1: Transmitting node is error passive.
• E0 Bit 30 XTD: Extended Identifier
0: 11-bit standard identifier.
1: 29-bit extended identifier.
• E0 Bit 29 RTR: Remote Transmission Request
0: Data frame transmitted.
1: Remote frame transmitted.
• E0 Bits 28:0 ID[28:0]: Identifier
Standard or extended identifier depending on bit XTD. A standard identifier is stored into ID[28:18].
• E1A/B Bits 31:24 MM[7:0]: Message Marker
Copied from Tx Buffer into Tx Event FIFO element for identification of Tx message status.
• E1A/B Bit 23:22 ET[1:0]: Event Type
0: Reserved
1: Tx event
2: Transmission in spite of cancellation (always set for transmissions in DAR mode)
3: Reserved
• E1A/B Bit 21 FDF: FD Format
0: Standard frame format.
1: CAN FD frame format (new DLC-coding and CRC).
• E1A/B Bit 20 BRS: Bit Rate Switch
0: Frame transmitted without bit rate switching.
1: Frame transmitted with bit rate switching.
• E1A/B Bits 19:16 DLC[3:0]: Data Length Code
0-8: CAN + CAN FD: frame with 0-8 data bytes transmitted.
9-15: CAN: frame with 8 data bytes transmitted.
9-15: CAN FD: frame with 12/16/20/24/32/48/64 data bytes transmitted
• E1A/B Bits 15:0 TXTS[15:0]: Tx Timestamp
Timestamp Counter value captured on start of frame transmission. Resolution depending on configuration of the Timestamp Counter Prescaler MCAN_TSCC.TCP.
• E1B Bit 4 TSC: Timestamp Captured
0: No timestamp captured
1: Timestamp captured and stored in TSU Timestamp register referenced by E1B.TXTSP
• E1B Bits 3:0 TXTSP[3:0]: Tx Timestamp Pointer
Number of the TSU Timestamp register (TS0..15) where the related timestamp is stored.