SPRUII0F May 2019 – June 2024 TMS320F28384D , TMS320F28384D-Q1 , TMS320F28384S , TMS320F28384S-Q1 , TMS320F28386D , TMS320F28386D-Q1 , TMS320F28386S , TMS320F28386S-Q1 , TMS320F28388D , TMS320F28388S
The MAC can be programmed to capture the timestamp of all packets received on the MII interface or to process packets to identify the valid PTP messages. Use the following options of the MAC_Timestamp_Control register to control the snapshot of the time to be sent to the application:
MAC_Timestamp_Control Register Bit | PTP Messages | ||
---|---|---|---|
SNAPTYPSEL | TSMSTRENA | TSEVNTENA | |
00 | x | 0 | SYNC, Follow_Up, Delay_Req, Delay_Resp |
00 | 0 | 1 | SYNC |
00 | 1 | 1 | Delay_Req |
01 | x | 0 | SYNC, Follow_Up, Delay_Req, Delay_Resp, Pdelay_Req, Pdelay_Resp, Pdelay_Resp_Follow_Up |
01 | 0 | 1 | SYNC, Pdelay_Req, Pdelay_Resp |
01 | 1 | 1 | Delay_Req, Pdelay_Req, Pdelay_Resp |
10 | x | x | SYNC, Delay_Req |
11 | x | x | Pdelay_Req, Pdelay_Resp |
The DMA returns the timestamp to the software inside the corresponding Receive Descriptor. The extended status, containing the timestamp message status and the IPC status, is written in normal descriptor RDES1 and the snapshot of the timestamp is written in RDES0 and RDES1 fields of context descriptor. The RDES0 field holds the 32 least-significant bits of the timestamp.