XIO2000AI TAOS [TEXAS ADVANCED OPTOELECTRONIC SOLUTIONS], XIO2000AI Datasheet - Page 39

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

3.4
3.4.1 I/O Characteristics
3.4.2 Clamping Voltage
April 2007 Revised October 2008
All supported message transactions are processed per the PCI Express Base Specification.
PCI Bus Interface
Figure 3−4 shows a 3-state bi-directional buffer that represents the I/O cell design for the PCI bus. Section
7.7, Electrical Characteristics over Recommended Operating Conditions, provides the electrical
characteristics of the PCI bus I/O cell.
In the bridge, the PCI bus I/O drivers are powered from the V
to input signals with 5.0-V peak-to-peak amplitudes.
For PCI bus interfaces operating at 66 MHz, all devices are required to output only 3.3-V peak-to-peak signal
amplitudes. For PCI bus interfaces operating at 33-MHz, devices may output either 3.3-V or 5.0-V
peak-to-peak signal amplitudes. The bridge accommodates both signal amplitudes.
Each PCI bus I/O driver cell has a clamping diode connected to the V
from excessive input voltage. If the PCI signaling is 3.3-V, then V
supply. If the PCI signaling is 5.0 V, then V
NOTE: The PCI bus interface on the bridge meets the ac specifications of the PCI Local Bus
Specification. Additionally, PCI bus terminals (input or I/O) must be held high or low to prevent
them from floating.
Assert_INTx
Deassert_INTx
PM_Active_State_Nak
PM_PME
PME_Turn_Off
PME_TO_Ack
ERR_COR
ERR_NONFATAL
ERR_FATAL
Unlock
Set_Slot_Power_Limit
Hot plug messages
Advanced switching messages
Vendor defined type 0
Vendor defined type 1
MESSAGE
Table 3−3. Messages Supported by the Bridge
Tied for Open Drain
Figure 3−4. 3-State Bidirectional Buffer
SUPPORTED
CCP
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
OE
(A04, J01) is connected to a 5.0-V power supply.
V CCP
DD_33
Received and processed
Received and processed
Received and processed
Received and processed
Transmitted upstream
Transmitted upstream
Transmitted upstream
Transmitted upstream
Transmitted upstream
Transmitted upstream
Transmitted upstream
Pad
Unsupported request
CCP
BRIDGE ACTION
power rail. Plus, the I/O driver cell is tolerant
Discarded
Discarded
Discarded
(A04, J01) is connected to a 3.3-V power
CCP
voltage rail that protects the cell
Feature/Protocol Descriptions
SCPS155C
29