LAN9353 Datasheet, PDF (429/523 Pages) Microchip Technology – Interfaces at up to 200Mbps via Turbo MII

LAN9353
15.8.8 1588 CLOCK RATE ADJUSTMENT REGISTER (1588_CLOCK_RATE_ADJ)
Offset:
Bank:
11Ch
na
Size:
32 bits
This register is used to adjust the rate of the 1588 Clock. Every 10 ns, 1588 Clock is normally incremented by 10 ns.
This register is used to occasionally change that increment to 9 or 11 ns.
Bits
Description
31 Clock Rate Adjustment Direction (1588_CLOCK_RATE_ADJ_DIR)
This field specifies if the 1588 Rate Adjustment causes the 1588 Clock to be
faster or slower than the reference clock.
0 = slower (1588 Clock increments by 9 ns)
1 = faster (1588 Clock increments by 11 ns)
30 RESERVED
29:0 Clock Rate Adjustment Value (1588_CLOCK_RATE_ADJ_VALUE)
This field indicates an adjustment to the reference clock period of the 1588
Clock in units of 2^-32ns. On each 10 ns reference clock cycle, this value is
added to the 32-bit sub-nanoseconds portion of the 1588 Clock. When the
sub-nanoseconds portion wraps around to zero, the 1588 Clock will be
adjusted by 1ns.
Type
R/W
RO
R/W
Default
0b
-
00000000h
 2015 Microchip Technology Inc.
DS00001925A-page 429