SLAU723A October 2017 – October 2018 MSP432E401Y , MSP432E411Y
The MAC supports an 80-bit timestamp with a lengthened seconds integer portion which is 48-bits wide. The Ethernet MAC System Time - Seconds (EMACTIMSEC) register at offset 0x708 and the Ethernet MAC System Time-Higher Word Seconds (EMACHWORDSEC) register at offset 0x724 comprise the seconds count. The 32-bit Ethernet MAC System Time - Nanoseconds (EMACTIMNANO) register contains the fractional portion of the timestamp units of nanoseconds. The nanoseconds register supports the following two modes:
Digital or binary rollover mode can be selected by programming the DGTLBIN bit of the EMACTIMSTCTRL register. Note that the timestamp maintained in the MAC is still 64 bits wide, but that the overflow to the upper 16-bits seconds register happens once in 130 years.