Datasheet

TSB12LV32 Data Formats
77
SGLS139B − October 2003 − Revised April 2004 TSB12LV32-EP
7.3.1 Extended Phy Packets
7.3.1.1 Ping Packets
The reception of a Phy ping packet causes the node identified by Phy_ID to transmit Self-ID packet(s) that
reflect the current configuration and status of the Phy. The ping packet provides a method of measuring the
round-trip delay of packets between two nodes on the bus that are farthest from one another in terms of cable
hops. The format of this packet is shown in Figure 7−12 and described in Table 7−9.
00 Phy_ID 00 type (0) 00000000
Logical inverse of the first quadlet
transmitted first
transmitted last
0000000000
Figure 7−12. Ping Packet Format
Table 7−9. Ping Packet Fields
FIELD NAME DESCRIPTION
Phy_ID Physical node identifier of the destination of this packet
type Extended Phy packet type (zero identifies ping packet)
7.3.1.2 Remote Access Packets
The remote access packet provides a method for a node to access the Phy registers of another node on the
bus. The reception of a remote access packet causes the node identified by the Phy_ID field to read the
selected Phy register and subsequntly return a remote reply packet that contains the current value of the Phy
register. The format of this packet is shown in Figure 7−13 and described in Table 7−10.
00 Phy_ID 00 type (8) cmnd00111
Logical inverse of the first quadlet
transmitted first
transmitted last
port000 000
Figure 7−13. Remote Access Packet Format
Table 7−10. Remote Access Packet Fields
FIELD NAME DESCRIPTION
Phy_ID Physical node identifier of the destination of this packet
type Extended Phy packet type (8 identifies command packet)
port This field selects one of the Phy ports
cmnd Command:
0 = NOP (No operation)
1 = Transmit TX_DISABLE_NOTIFY, then disable port
2 = Initiate suspend (i.e., become a suspend initiator)
4 = Clear the port’s Fault bit to zero
5 = Enable port
6 = Resume port