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

Datasheet

14.2.5IEEE 1588

This section details the IEEE 1588 timestamp related registers. Each port of the LAN9312 has a 1588 timestamp block with 8 related registers, 4 for transmit capture and 4 for receive capture. These sets of registers are identical in functionality for each port, and thus their register descriptions have been consolidated. In these cases, the register names will be amended with a lowercase “x” in place of the port designation. The wildcard “x” should be replaced with “1”, “2”, or “MII” for the Port 1, Port 2, and Port 0(Host MAC) respectively. A list of all the 1588 related registers can be seen in Table 14.1. For more information on the IEEE 1588, refer to Chapter 11, "IEEE 1588 Hardware Time Stamp Unit," on page 154.

14.2.5.1Port x 1588 Clock High-DWORD Receive Capture Register (1588_CLOCK_HI_RX_CAPTURE_x)

 

Offset:

Port 1: 100h

Size:

32 bits

 

 

 

Port 2: 120h

 

 

 

 

 

 

Port 0: 140h

 

 

 

 

 

 

 

 

 

 

 

BITS

 

DESCRIPTION

 

 

TYPE

DEFAULT

 

 

 

 

 

 

 

31:0

Timestamp High (TS_HI)

 

 

 

RO

00000000h

 

This field contains the high 32-bits of the timestamp taken on the receipt of

 

 

 

a 1588 Sync or Delay_Req packet.

 

 

 

 

 

 

 

 

 

Note: The selection between Sync or Delay_Req packets is based on the corresponding

 

master/slave bit in the 1588 Configuration Register (1588_CONFIG).

 

Note: There are multiple instantiations of this register, one for each port of the LAN9312. Refer to Section 14.2.5 for additional information.

Note: For Port 0(Host MAC), receive is defined as data from the switch fabric, while transmit is to the switch fabric.

SMSC LAN9312

201

Revision 1.4 (08-19-08)

 

DATASHEET