In the Coarse Update mode (TSCFUPDT bit in Register 448), the value in this register is added to the system time every clock cycle of clk_ptp_ref_i. In the Fine Update mode, the value in this register is added to the system time whenever the Accumulator gets an overflow.
Module Instance Base Address Register Address
emac0 0xFF700000 0xFF700704
emac1 0xFF702000 0xFF702704

Offset: 0x704

Access: RW

Important: To prevent indeterminate system behavior, reserved areas of memory must not be accessed by software or hardware. Any area of the memory map that is not explicitly defined as a register space or accessible memory is considered reserved.
Bit Fields
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



RW 0x0

Sub_Second_Increment Fields

Bit Name Description Access Reset
7:0 ssinc

The value programmed in this field is accumulated every clock cycle (of clk_ptp_i) with the contents of the sub-second register. For example, when PTP clock is 50 MHz (period is 20 ns), you should program 20 (0x14) when the System Time-Nanoseconds register has an accuracy of 1 ns (TSCTRLSSR bit is set). When TSCTRLSSR is clear, the Nanoseconds register has a resolution of ~0.465ns. In this case, you should program a value of 43 (0x2B) that is derived by 20ns/0.465.

RW 0x0