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Solution ID: rd05072008_61
Last Modified: May 08, 2008
Product Category: Devices
Product Area: Gigabit Transceivers
Product Sub-area: Protocols
Problem
The Quartus® II compiler fails for Stratix II GX designs with transceivers configured in bonded x4 (PCI Express (PIPE) x4, XAUI and Basic x4) and bonded x8 (PCI Express (PIPE) x8) configurations depending on channel placement. Are there any channel placement constraints in these configurations?
Is there any recommendation for lane mapping between the Stratix II GX transceiver physical channels to the PCI Express edge connector?
Solution
Quartus® II software requires specific channel placements for the following bonded channel configurations to compile the design succesfully.
1) x4 Bonded Channel Configurations:
In PCI Express (PIPE) x4 and XAUI modes, both the transmitter and receiver channels are bonded. In Basic x4 mode, only the transmitter channels are bonded.
a) For a PCI Express (PIPE) x4 or XAUI implementation, you must connect the ALT2GXB logical channels to the physical channels as follows:
- Logical Channel 0 (tx_dataout[0]/rx_datain[0]) -> Physical Channel 0 in the Transceiver Block
- Logical Channel 1 (tx_dataout[1]/rx_datain[1]) -> Physical Channel 1 in the Transceiver Block
- Logical Channel 2 (tx_dataout[2]/rx_datain[2]) -> Physical Channel 2 in the Transceiver Block
- Logical Channel 3 (tx_dataout[3]/rx_datain[3]) -> Physical Channel 3 in the Transceiver Block
b) For a Basic x4 implementation, you must connect the ALT2GXB logical channels to the physical channels as follows:
- Logical Channel 0 (tx_dataout[0]) -> Physical Channel 0 in the Transceiver Block
- Logical Channel 1 (tx_dataout[1]) -> Physical Channel 1 in the Transceiver Block
- Logical Channel 2 (tx_dataout[2]) -> Physical Channel 2 in the Transceiver Block
- Logical Channel 3 (tx_dataout[3]) -> Physical Channel 3 in the Transceiver Block
The Quartus® II software generates compilation errors when the logical channels are not connected to the physical channels as recommended above.
For a x4 bonded configuration, Altera recommends connecting the physical channels 0, 1, 2, and 3 in the Transceiver block to the respective connector’s Lanes 0, 1, 2, and 3, respectively.
Figure 1.Shows the legal physical channel to x4 lane mapping in Stratix II GX devices with four transceiver blocks.
View full size
2) x8 Bonded Channel Configurations:
For a PCI Express (PIPE) x8 implementation, you must connect the ALT2GXB logical channels to the physical channels as follows:
- Logical Channel 0 (tx_dataout[0]/rx_datain[0]) -> Physical Channel 0 in the Master Transceiver Block
- Logical Channel 1 (tx_dataout[1]/rx_datain[1]) -> Physical Channel 1 in the Master Transceiver Block
- Logical Channel 2 (tx_dataout[2]/rx_datain[2]) -> Physical Channel 2 in the Master Transceiver Block
- Logical Channel 3 (tx_dataout[3]/rx_datain[3]) -> Physical Channel 3 in the Master Transceiver Block
- Logical Channel 4 (tx_dataout[4]/rx_datain[4]) -> Physical Channel 0 in the Slave Transceiver Block
- Logical Channel 5 (tx_dataout[5]/rx_datain[5]) -> Physical Channel 1 in the Slave Transceiver Block
- Logical Channel 6 (tx_dataout[6]/rx_datain[6]) -> Physical Channel 2 in the Slave Transceiver Block
- Logical Channel 7 (tx_dataout[7]/rx_datain[7]) -> Physical Channel 3 in the Slave Transceiver Block
The Quartus® II software generates compilation errors when the logical channels are not connected to the physical channels as recommended above.
For a PCI Express x8 link, Altera recommends connecting the physical channels 0, 1, 2, 3, 4, 5, 6, and 7 in the transceiver block to the PCI Express edge connector Lanes 0, 1, 2, 3, 4, 5, 6, and 7, respectively.
Figure 2.Shows the legal physical channel to PCI Express x8 lane mapping in Stratix II GX devices with four transceiver blocks.
View full size
For legal physical channel to PCI Express x8 lane mapping in all other Stratix II GX devices, refer to the “Transceiver Clock Distribution” section in the “Stratix II GX Transceiver Architecture Overview” chapter in volume 2 of the Stratix II GX Device Handbook.
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Altera does not warrant that this solution will work for the customer's intended purpose and disclaims all liability for use of or reliance on the solution.
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