188.8.131.52. Guideline: Pin Placement for Differential Channels
Each I/O bank contains its own PLL. The I/O bank PLL can drive all receiver and transmitter channels in the same bank, and transmitter channels in adjacent I/O banks. However, the I/O bank PLL cannot drive receiver channels in another I/O bank or transmitter channels in non-adjacent I/O banks.
PLLs Driving Differential Transmitter Channels
For differential transmitters, the PLL can drive the differential transmitter channels in its own I/O bank and adjacent I/O banks. However, the PLL cannot drive the channels in a non-adjacent I/O bank.
The I/O bank PLL can drive the differential transmitter channels in an adjacent I/O bank only in a wide LVDS SERDES Intel® FPGA IP transmitter interface that spans multiple I/O banks, where:
- With tx_outclock enabled—the transmitter has more than 22 channels
- With tx_outclock disabled—the transmitter has more than 23 channels
For an LVDS SERDES Intel® FPGA IP transmitter interface contained within a single I/O bank, drive the transmitter using the PLL in the same I/O bank.
PLLs Driving DPA-Enabled Differential Receiver Channels
For differential receivers, the PLL can drive only the channels within the same I/O bank.
Each differential receiver in an I/O bank has a dedicated DPA circuit to align the phase of the clock to the data phase of its associated channel. If you enable a DPA channel in a bank, you can assign the unused I/O pins in the bank to single-ended or differential I/O standards that has the same VCCIO voltage level used by the bank.
DPA usage adds some constraints to the placement of high-speed differential receiver channels. The Intel® Quartus® Prime compiler automatically checks the design and issues error messages if there are placement guidelines violations. Adhere to the guidelines to ensure proper high-speed I/O operation.
PLLs Driving DPA-Enabled Differential Receiver and Transmitter Channels in LVDS Interface Spanning Multiple I/O Banks
If you use both differential transmitter and DPA-enabled receiver channels in a bank, the PLL can drive the transmitters spanning multiple adjacent I/O banks, but only the receivers in its own I/O bank.
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