TSI148-133CL IDT, Integrated Device Technology Inc, TSI148-133CL Datasheet - Page 383

• Manufacturer Part Number: TSI148-133CL
• Description: IC PCI-VME BRIDGE 456PBGA
• Manufacturer: IDT, Integrated Device Technology Inc
• Series: Tsi148&Trade;r

Specifications of TSI148-133CL

• Applications: PCI-to-VME Bridge
• Interface: PCI
• Voltage - Supply: 3.3V
• Package / Case: 456-PBGA
• Mounting Type: Surface Mount
• Package Type: BGA
• Rad Hardened: No
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 800-1906

B.3
B.3.1
Tsi148 PCI/X-to-VME Bus Bridge User Manual
80A3020_MA001_13
Recommended Board Layout Guidelines
When laying out a board with the Tsi148 , the device should be placed as close as possible to
the center of the board (that is, placed in between the P1 and P2 connectors). IDT
recommends connecting all Tsi148 VME signals to the VMEbus backplane through the TI
TISN74VMEH22501/22501A transceivers.
In order to satisfy VME requirements, all sources of drive on the VMEbus must be no
further than two inches from the backplane. This design minimizes any potential loading
and reflection problems. IDT recommends the traces from the TISN74VMEH22501/22501A
transceivers to the P1 and P2 connectors be no more than two inches in length. IDT also
recommends the Tsi148 be placed in an orientation on the board that minimizes the distance
to the P1 and P2 connectors however, the Tsi148 device orientation is board specific.
Figure 49
For more information on IDT board recommendations, refer to the Tsi148 Schematic Review
Checklist available from the IDT website at www.IDT.com.
Figure 49:
Trace Length Recommendations
It is good design practice to keep all Tsi148 VME signal trace lengths from the device to the
transceivers within a 15 to 20 percent nominal spread. For the majority of the Tsi148 signals
a trace length an inch to either side of the nominal is recommended. It is also recommended
that the inputs and outputs of the key VME control signals (that is, AS, DS0, DS1, DTACK,
RETRY, and BERR) be routed with trace lengths equal to the nominal trace length.
P2
shows an example of how the Tsi148 device was oriented in a successful design.
Tsi148 PBGA Orientation
Transceivers
Pin AF01
Less than 2”
Tsi148
B. Hardware Implementation > Recommended Board Layout Guidelines
Transceivers
P1
Less than 2”
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