High Performance Two Port 10/100 Managed Ethernet Switch with 32-Bit Non-PCI CPU Interface
Datasheet
14.2.5
IEEE 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.
14.2.5.1
Port x 1588 Clock High-DWORD Receive Capture Register (1588_CLOCK_HI_RX_CAPTURE_x)
Offset:
Port 1: 100h
Port 2: 120h
Port 0: 140h
Size:
32 bits
BITS
DESCRIPTION
TYPE
DEFAULT
31:0
Timestamp High (TS_HI)
This field contains the high 32-bits of the timestamp taken on the receipt of
a 1588 Sync or Delay_Req packet.
RO
00000000h
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 1.2 (04-08-08)
DATASHEET
SMSC [ SMSC CORPORATION ]
