gmacgrp_sub_second_increment

         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
`i_emac_emac0`	`0xFF800000`	`0xFF800704`
`i_emac_emac1`	`0xFF802000`	`0xFF802704`
`i_emac_emac2`	`0xFF804000`	`0xFF804704`

Offset: 0x704

Access: RW

Important: The value of a reserved bit must be maintained in software. When you modify registers containing reserved bit fields, you must use a read-modify-write operation to preserve state and prevent indeterminate system behavior.

Bit Fields
31	30	29	28	27	26	25	24	23	22	21	20	19	18	17	16
`Reserved`
15	14	13	12	11	10	9	8	7	6	5	4	3	2	1	0
`Reserved`								`ssinc` `RW 0x0`

gmacgrp_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`

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