Interlaken (2nd Generation) Intel® FPGA IP User Guide

ID 683396
Date 12/04/2023
Public
Document Table of Contents

5.1. Clock and Reset Interface Signals

Table 28.  Clock and Reset Interface Signals
Signal Name Feature Support Width (Bits) I/O Direction Description
pll_ref_clk / pll_ref_clk[1:0] 11 ILK and ILA 1/2 Input Transceiver reference clock for the RX CDR PLL in IP core variations that target a Intel® Stratix® 10 device. The sets of valid frequencies vary with the per-lane data rate of the transceivers as following:
Per-Lane Data Rate (Gbps) Valid pll_ref_clk Frequencies (MHz)
6.25 156.25, 195.3125, 250, 312.5, 390.625, 480.7692313, 500 12, 62512
10.3125 156.25, 206.25, 257.8125, 322.265625, 412.5, 491.07142813, 515.62512, 644.5312512
12.5 156.25, 195.3125, 250, 312.5, 390.625, 500, 62512
25.28 126.412, 158.0, 197.5, 252.8, 320.012, 395.0, 486.153846 13, 505.612
25.78 159.135802, 201.40625, 250.29126212, 322.25, 402.8125, 495.76923113, 500.58252412
25.78125 159.14351912, 159.14351813, 201.41601612, 201.41601513, 250.30339812, 322.265625, 402.832031, 500.60679612, 495.79326913
26.562514 156.25, 210.813492, 312.5, 390.625, 491.898148
Note: pll_ref_clk[1] is only available when you enable Preserve unused transceiver channels for PAM4 parameter in E-tile PAM4 mode IP variations.
tx_usr_clk ILK only 1 Input Transmit side user data interface clock. The lower frequency of tx_usr_clk increases the latency of data path.
rx_usr_clk ILK only 1 Input Receive side user data interface clock. The lower frequency of rx_usr_clk increases the latency of data path.
clk_tx_common ILK and ILA 1 Output Transmit PCS common lane clock driven by the SERDES transmit PLL.
The frequency is given by the following equation:
Frequency of clk_tx_common = transceiver data rate / PMA_WIDTH
For example, the clock rate is 322 MHz at 10.3125 Gbps transceiver speed with 32 bits.
The valid frequencies per lane data rate are as below:
Data Rate (Gbps) E-tile L- and H-tile
PMA_WIDTH clk_tx_common PMA_WIDTH clk_tx_common
6.25 64 97.656250 32 195.3125
10.3125 64 161.132813 32 (For number of segments = 1) 322.265625
64 (For number of segments = 2) 161.1328125
12.5 64 195.3125 64 195.3125
40 (Only for number of segments =1 and 12x12.5 Gbps combination) 312.5
25.28 64 395.0 64 395.0
25.78 64 402.8125 64 402.8125
25.78125 64 402.8320 64 402.8320
26.5625 64 415.039063 N/A N/A
clk_rx_common ILK and ILA 1 Output Receive PCS common lane clock driven by CDR in transceiver.
The frequency is given by the following equation:
Frequency of clk_rx_common = transceiver data rate / PMA_WIDTH
For example, the clock rate is 322 MHz at 10.3125 Gbps transceiver speed with 32 bits PMA_WIDTH. The valid frequencies for clk_rx_common are same as clk_tx_common.
reset_n ILK and ILA 1 Input Active-low asynchronous reset signal.
tx_usr_srst ILK and ILA 1 Output Transmit-side reset output signal. Indicates the transmit side user data interface is resetting. This signal is synchronous with tx_usr_clk.
rx_usr_srst ILK and ILA 1 Output Receive-side reset output. Indicates the receive side user data interface is resetting. This signal is synchronous with rx_usr_clk.
mac_clkin ILK and ILA 1 Input This clock signal is only available in IP core variations that target an E-tile PAM4 device variations. This signal must be driven by a PLL and must use the same clock source that drives the pll_ref_clk.
11 When you enable Preserve unused transceiver channels for PAM4 parameter, an additional reference clock port is added to preserve the unused PAM4 slave channel.
12 Only available in H-tile and L-tile device variations.
13 Only available in NRZ E-tile device variations.
14 Only available in PAM4 E-tile device variations.