XIO2000AI TAOS [TEXAS ADVANCED OPTOELECTRONIC SOLUTIONS], XIO2000AI Datasheet - Page 58

• Manufacturer Part Number: XIO2000AI
• Description: PCI Express to PCI Bus Translation Bridge
• Manufacturer: TAOS [TEXAS ADVANCED OPTOELECTRONIC SOLUTIONS]

Feature/Protocol Descriptions
48
SCPS155C
The link power management (LPM) state machine manages active state power by monitoring the PCI Express
transaction activity. If no transactions are pending and the transmitter has been idle for at least the minimum
time required by the PCI Express Specification, then the LPM state machine transitions the link to either the
L0s or L1 state. By reading the bridge’s L0s and L1 exit latency in the link capabilities register, the system
software may make an informed decision relating to system performance versus power savings. The ASLPMC
field in the link control register provides an L0s-only option, L1-only option, or both L0s and L1 option.
Finally, the bridge generates the PM_Active_State_Nak Message if a PM_Active_State_Request_L1 DLLP
is received on the PCI Express interface and the link cannot be transitioned to L1.
PCI express reference clock input (REFCLK)
PCI clock input (CLK)
Secondary PCI bus clock outputs (CLKOUT6:0)
CLOCK SOURCE
Table 3−15. Clocking In Low Power States
D0/L0
On
On
On
D1/L1
On
Off
On
D2/L1
On
Off
On
D3/L2/L3
On/Off
On/Off
April 2007 Revised October 2008
Off