High Performance Two Port 10/100 Managed Ethernet Switch with 32-Bit Non-PCI CPU Interface

Datasheet

14.2.5.141588 Clock Low-DWORD Register (1588_CLOCK_LO)

Offset:

174h

Size:

32 bits

This read/write register combined with 1588 Clock High-DWORD Register (1588_CLOCK_HI) form the 64-bit 1588 Clock value. The 1588 Clock value is used for all 1588 timestamping. The 1588 Clock has a base frequency of 100MHz, which can be adjusted via the 1588 Clock Addend Register (1588_CLOCK_ADDEND) accordingly. Refer to Chapter 11, "IEEE 1588 Hardware Time Stamp Unit," on page 154 for additional information.

BITS

DESCRIPTION

TYPE

DEFAULT

 

 

 

 

31:0

Clock Low (CLOCK_LO)

R/W

00000000h

 

This field contains the low 32-bits of the 64-bit 1588 Clock.

 

 

 

 

 

 

Note: Both this register and the 1588 Clock High-DWORD Register (1588_CLOCK_HI) must be written for either to be affected.

Note: The value read is the saved value of the 1588 Clock when the 1588_CLOCK_SNAPSHOT bit in the 1588 Command Register (1588_CMD) is set.

Revision 1.4 (08-19-08)

214

SMSC LAN9312

 

DATASHEET