VT6306 datasheet(48/59 Pages) VIA

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VT6306 PCI 1394a Host Controller

Revision 1.16 July 19, 2002

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Functional Descriptions

PHY-Configuration Packet

The VT6306 PHY will respond to every PHY configuration packet which it receives on the bus, or from the host for transmission

on the bus. The packet has the format shown in the figure below. The fields in the PHY configuration packet are interpreted as

shown in the table below. Note that either or both of R and T must be set to 1.

Note: Bit 0 (the lsb) is on the left in the above diagram

Figure 8. Configuration Packet Format

Table 9. PHY Configuration Packet Fields

Field Name

Meaning

Root_ID

Physical ID. The physical node identifier of the node to become root on next reset

Set root. The Force_Root bit in the VT6306 PHY is set if R=1 and Root_ID = the Node_ID of this node

Set gap count. If T=1, then the value of the gap count register in the VT6306 is set to gap_cnt.

Gap_cnt

Gap_Count value. New value of Gap Count register

Ping Packet

The VT6306 supports the use of ping for bus round trip calculation. The ping packet has the format shown in the figure below.

When the VT6306 receives a ping packet from the bus or from the local link addressed to the node, it responds immediately

(without arbitration) with a Self_ID packet to both the bus and the local link.

Note: Bit 0 (the lsb) is on the left in the above diagram

Figure 9. Ping Packet Format

VT6306 Datasheet(PDF) 48 Page - VIA Technologies, Inc.