stm32 /stm32h5 /STM32H573 /ETH /ETH_MACTSCR

Enable Timestamp When this bit is set, the timestamp is added for Transmit and Receive packets. When disabled, timestamp is not added for transmit and receive packets and the Timestamp Generator is also suspended. You need to initialize the Timestamp (system time) after enabling this mode. On the Receive side, the MAC processes the 1588 packets only if this bit is set.

Fine or Coarse Timestamp Update When this bit is set, the Fine method is used to update system timestamp. When this bit is reset, Coarse method is used to update the system timestamp.

Initialize Timestamp When this bit is set, the system time is initialized (overwritten) with the value specified in the System time seconds update register (ETH_MACSTSUR) and System time nanoseconds update register (ETH_MACSTNUR). This bit should be zero before it is updated. This bit is reset when the initialization is complete.

Update Timestamp When this bit is set, the system time is updated (added or subtracted) with the value specified in System time seconds update register (ETH_MACSTSUR) and System time nanoseconds update register (ETH_MACSTNUR). This bit should be zero before updating it. This bit is reset when the update is complete in hardware.

Update Addend Register When this bit is set, the content of the Timestamp Addend register is updated in the PTP block for fine correction. This bit is cleared when the update is complete. This bit should be zero before it is set.

Enable Timestamp for All Packets When this bit is set, the timestamp snapshot is enabled for all packets received by the MAC.

Timestamp Digital or Binary Rollover Control When this bit is set, the Timestamp Low register rolls over after 0x3B9A_C9FF value (that is, 1 nanosecond accuracy) and increments the timestamp (High) seconds. When this bit is reset, the rollover value of subsecond register is 0x7FFF_FFFF. The subsecond increment must be programmed correctly depending on the PTP reference clock frequency and the value of this bit.

Enable PTP Packet Processing for Version 2 Format When this bit is set, the IEEE 1588 version 2 format is used to process the PTP packets. When this bit is reset, the IEEE 1588 version 1 format is used to process the PTP packets. The IEEE 1588 formats are described in ‘PTP Processing and Control’.

Enable Processing of PTP over Ethernet Packets When this bit is set, the MAC receiver processes the PTP packets encapsulated directly in the Ethernet packets. When this bit is reset, the MAC ignores the PTP over Ethernet packets.

Enable Processing of PTP Packets Sent over IPv6-UDP When this bit is set, the MAC receiver processes the PTP packets encapsulated in IPv6-UDP packets. When this bit is clear, the MAC ignores the PTP transported over IPv6-UDP packets.

Enable Processing of PTP Packets Sent over IPv4-UDP When this bit is set, the MAC receiver processes the PTP packets encapsulated in IPv4-UDP packets. When this bit is reset, the MAC ignores the PTP transported over IPv4-UDP packets. This bit is set by default.

Enable Timestamp Snapshot for Event Messages When this bit is set, the timestamp snapshot is taken only for event messages (SYNC, Delay_Req, Pdelay_Req, or Pdelay_Resp). When this bit is reset, the snapshot is taken for all messages except Announce, Management, and Signaling. For more information about the timestamp snapshots, see Table634: Timestamp Snapshot Dependency on ETH_MACTSCR bits.

Enable Snapshot for Messages Relevant to Master When this bit is set, the snapshot is taken only for the messages that are relevant to the master node. Otherwise, the snapshot is taken for the messages relevant to the slave node.

Select PTP packets for Taking Snapshots These bits, along with Bits 15 and 14, define the set of PTP packet types for which snapshot needs to be taken. The encoding is given in Table634: Timestamp Snapshot Dependency on ETH_MACTSCR bits.

Enable MAC Address for PTP Packet Filtering When this bit is set, the DA MAC address (that matches any MAC Address register) is used to filter the PTP packets when PTP is directly sent over Ethernet. When this bit is set, received PTP packets with DA containing a special multicast or unicast address that matches the one programmed in MAC address registers are considered for processing as indicated below, when PTP is directly sent over Ethernet. For normal timestamping operation, MAC address registers 0 to 31 is considered for unicast destination address matching. For PTP offload, only MAC address register 0 is considered for unicast destination address matching.

Transmit Timestamp Status Mode When this bit is set, the MAC overwrites the earlier transmit timestamp status even if it is not read by the software. The MAC indicates this by setting the TXTSSMIS bit of the Tx timestamp status nanoseconds register (ETH_MACTXTSSNR) register. When this bit is reset, the MAC ignores the timestamp status of current packet if the timestamp status of previous packet is not read by the software. The MAC indicates this by setting the TXTSSMIS bit of the Tx timestamp status nanoseconds register (ETH_MACTXTSSNR).

AV 802.1AS Mode Enable When this bit is set, the MAC processes only untagged PTP over Ethernet packets for providing PTP status and capturing timestamp snapshots, that is, IEEE 802.1AS operating mode. When PTP offload feature is enabled, for the purpose of PTP offload, the transport specific field in the PTP header is generated and checked based on the value of this bit.