F-Tile Ethernet Multirate Intel® FPGA IP User Guide

ID 714307
Date 5/01/2024
Public
Document Table of Contents

2.2. Clock Signals

This section describes required clock connections and clock signals for the F-Tile Ethernet Multirate IP core.

The Ethernet Multirate IP core uses the o_clk_pll common system PLL clock for all ports within a reconfiguration group.

The i_reconfig_clk input is a common clock for the Avalon® memory-mapped interfaces of all ports within a reconfiguration group. You must use the same reconfiguration clock in the F-Tile Dynamic Reconfiguration IP core and all F-Tile Ethernet Multirate IP core instances targeting a particular tile.

You must make the following clock connections:
  • The i_clk_ref and the i_clk_sys clocks drives the IP core.
  • The output clock o_clk_pll drives both the i_clk_rx and the i_clk_tx input signals.
Figure 3. Typical Clock ConnectionsThis diagram displays Ethernet Multirate IP core and its related clock signals.
Table 12.  Clock SignalsThis table lists the common input clock signals for the Ethernet Multirate IP core.
Signal Name Number of Ports I/O Direction Description
Clock Inputs
i_clk_tx 1, 2, or 4 Input TX datapath clock

This clock drives the active TX interface for the port.

This clock source is:

o_clk_pll clock unless you enabled Enable asynchronous adapter clocks parameter.

i_clk_rx 1, 2, or 4 Input RX datapath clock

This clock drives the active RX interface for the port.

This clock source is:

o_clk_pll clock unless you enabled Enable asynchronous adapter clocks parameter.

i_reconfig_clk 1, 2, or 4 Input Avalon® memory-mapped interface reconfiguration clock

The interface uses this clock to access control status registers (CSRs). The clock supports 100 to 250 MHz frequency.

When PTP is enabled, the i_reconfig_clk frequency supports the range of 100 to 250 MHz.

i_clk_ref 1, 2, or 4 Input PMA reference clock
F-Tile Reference and System PLL Clock Intel® FPGA IP drives this clock.
  • 156.25 MHz is the recommended frequency for all Ethernet modes. This is the only supported frequency when using FHT PMA or when auto-negotiation and link training is enabled.
  • 312.5 MHz when using FGT PMA with Firecode or RS (528,514) FEC and without auto-negotiation and link training
  • 322.265625 MHz when using FGT PMA with Firecode or RS (528,514) FEC without auto-negotiation and link training
The clock source depends on the PMA selection.
  • When using FGT PMA, the clock source is the out_refclk_fgt_i output signal from the F-Tile Reference and System PLL Clocks Intel® FPGA IP.
  • When using FHT PMA, the clock source is the out_fht_cmmpll_clk_i output signal from the F-Tile Reference and System PLL Clocks Intel® FPGA IP.

Unless the Custom cadence parameter is enabled, the clock must be PPM matched to the i_clk_sys clock.

i_clk_pll 1, 2, or 4 Input PTP-related datapath clock

This clock drives the internal datapath clock for the port when both, Enable IEEE 1588 PTP and Enable asynchronous adapter clocks parameters, are enabled.

This clock source is the o_clk_pll output of the PTP tile adapter. You must use a single clock source when using a multiple PTP ports in your design.

Supports the following frequencies:
  • 402.83203125 MHz or higher for all Ethernet modes without FEC, with IEEE 802.3 BASE-R Firecode (CL74), or IEEE 802.3 RS(528,514) (CL91). The system PLL must be of 805.6640625 MHz frequency or higher.
  • 415.0390625 MHz or higher for all Ethernet modes with IEEE 802.3 RS(544,514) (CL134), with Ethernet Technology Consortium RS(272, 258). The system PLL must be of 830.078125 MHz frequency or higher.
  • Custom system PLL frequency supports 402.83203125 MHz or higher frequency

When Enable IEEE 1588 PTP parameter is disabled, connect this port to 1'b0.

i_clk_sys 1, 2, or 4 Input Ethernet system clock

F-Tile Reference and System PLL Clocks Intel® FPGA IP drives this clock.

Unless Custom cadence parameter is enabled, the clock frequency depends on the FEC type:
  • 805.6640625 MHz or higher for all Ethernet modes without FEC, or with IEEE 802.3 BASE-R Firecode (CL74), or IEEE 802.3 RS(528,514) (CL91)
  • 830.078125 MHz or higher for all Ethernet modes with IEEE 802.3 RS(544,514) (CL134), Ethernet Technology Consortium RS(272, 258)
  • 322.265625 MHz or higher is also supported for 10GE without PTP
You must specify this frequency in the F-Tile Ethernet Multirate Intel® FPGA IP System PLL frequency IP parameter and in the F-Tile Reference and System PLL Clocks Intel® FPGA IP Mode of system PLL IP parameter.
Note: The i_clk_sys is a virtual signal. In simulation, the signal displays as 0.

Connect to the out_systempll_clk_i signal from the F-Tile Reference and System PLL Clocks Intel® FPGA IP.

Clock Outputs
o_clk_pll 1, 2, or 4 Output System PLL clock

Clock derived from the F-Tile System PLL associated with the Ethernet IP port. The o_clk_pll frequency is equal to PLL frequency divided by 2. The following shows the o_clk_pll frequency unless you enabled custom system PLL frequency.

Supports the following frequencies:
  • 402.83203125 MHz or higher for all Ethernet modes without FEC, with IEEE 802.3 BASE-R Firecode (CL74), or IEEE 802.3 RS(528,514) (CL91). The system PLL must be of 805.6640625 MHz frequency or higher.
  • 415.0390625 MHz or higher for all Ethernet modes with IEEE 802.3 RS(544,514) (CL134), with Ethernet Technology Consortium RS(272, 258). The system PLL must be of 830.078125 MHz frequency or higher.
  • 161.1328125 MHz or higher for 10GE without enabled PTP. The system PLL must be of 322.265625 MHz frequency or higher.
  • Custom system PLL frequency divided by 2, if custom system PLL frequency is used
Table 13.  Divided Clock Outputs SignalsThis table lists the divided clock outputs for the Ethernet Multirate IP core. Each reconfiguration group has separate divided clock outputs.
Signal Name Number of Ports I/O Direction Description
o_p0_clk_tx_div 1, 2, or 4 Output
Supports the following frequencies:
  • 156.25 MHz for 10GE
  • 312.5 MHz for 40GE
  • 390.625 MHz for all other Ethernet modes

Clock recovered from the TX SERDES rate divided by either 33/66/68, depending on the FEC mode and Ethernet mode parameters. The o_clk_tx_div is equal to:

  • TX SERDES rate divided by 33 for 40GE.
  • TX SERDES rate divided by 66 when FEC mode parameter is set to one of the following:
    • None except for 40GE
    • IEEE 802.3 BASE-R Firecode (CL74)
    • IEEE 802.3 RS(528,514) (CL91)
  • TX SERDES rate divided by 68 when FEC mode parameter is set to one of the following:
    • IEEE 802.3 RS(544,514) (CL134)
    • Ethernet Technology Consortium RS(272, 258)
o_p0_clk_rec_div64 1, 2, or 4 Output
Supports the following frequencies:
  • 161.1328125 MHz ± 200 PPM for 10GE/40GE
  • 402.83203125 MHz ± 200 PPM for Ethernet modes without FEC (except 10GE and 40GE), with IEEE 802.3 BASE-R Firecode (CL74), and IEEE 802.3 RS(528,514) (CL91)
  • 415.0390625 MHz ± 200 PPM for Ethernet modes with IEEE 802.3 RS(544,514) (CL134) and Ethernet Technology Consortium RS(272, 258)

Clock derived from RX recovered clock, divided by 64.

o_p0_clk_rec_div 1, 2, or 4 Output
Supports the following frequencies:
  • 156.25 MHz ± 200PPM for 10GE
  • 312.50 MHz ± 200PPM for 40GE
  • 390.625 MHz ± 200PPM for all other Ethernet modes

Clock derived from the RX recovered clock divided by either 33/66/68, depending on the FEC mode parameter. The o_clk_rec_div is equal to:

  • RX SERDES rate divided by 33 for 40GE
  • RX SERDES rate divided by 66 when FEC mode parameter is set to one of the following:
    • None except for 40GE
    • IEEE 802.3 BASE-R Firecode (CL74)
    • IEEE 802.3 RS(528,514) (CL91)
  • RX SERDES rate divided by 68 when FEC mode parameter is set to one of the following:
    • IEEE 802.3 RS(544,514) (CL134)
    • Ethernet Technology Consortium RS(272, 258)
o_p1_clk_tx_div 2 or 4 Output Same as the o_p0_clk_tx_div signal description
o_p1_clk_rec_div64 2 or 4 Output Same as the o_p0_clk_rec_div64 signal description
o_p1_clk_rec_div 2 or 4 Output Same as the o_p0_clk_rec_div signal description
o_p2_clk_tx_div 4 Output Same as the o_p0_clk_tx_div signal description
o_p2_clk_rec_div64 4 Output Same as the o_p0_clk_rec_div64 signal description
o_p2_clk_rec_div 4 Output Same as the o_p0_clk_rec_div signal description
o_p3_clk_tx_div 4 Output Same as the o_p0_clk_tx_div signal description
o_p3_clk_rec_div64 4 Output Same as the o_p0_clk_rec_div64 signal description
o_p3_clk_rec_div 4 Output Same as the o_p0_clk_rec_div signal description

The locked status output is common since all ports in the reconfiguration group share the same system PLL clock. The transceiver PLL and RX CDR lock signals are port-specific dependent on the Number of Ports setting.

Table 14.  Clock Status SignalsThis table lists the clock status ports for the Ethernet Multirate IP core. Use these ports to hold the circuits that use clock sources from the IP core in reset until the PLLs driving the clocks are locked. All signals are asynchronous.
Signal Name Number of Ports I/O Direction Description
o_sys_pll_locked 1, 2, or 4 Output Indicates the locked system PLL.

Do not use the o_clk_pll clock until the o_sys_pll_locked clock is high.

o_p0_tx_pll_locked 1, 2, or 4 Output Indicates the TX PLL driving clock signal from the core is locked.

Do not use the o_clk_tx_div clock until the o_p0_tx_pll_locked clock is high.

o_p0_cdr_lock 1, 2, or 4 Output Indicates that the recovered clocks are locked to data.

Do not use the o_clk_rec_div64 or o_clk_rec_div clocks until the o_p0_cdr_lock clock is high.

o_p1_tx_pll_locked 2 or 4 Output If you set the number of ports to 2 or 4, indicates the TX PLL driving clock signal from the core port1 is locked.

Do not use the o_clk_tx_div clock until the o_p1_tx_pll_locked clock is high.

o_p1_cdr_lock 2 or 4 Output If you set the number of ports to 2 or 4, indicates that the recovered clocks from port 1 are locked to data.

Do not use the o_clk_rec_div64 or o_clk_rec_div clocks until the o_p1_cdr_lock clock is high.

o_p2_tx_pll_locked 4 Output If you set the number of ports to 4, indicates the TX PLL driving clock signal from the core port2 is locked.

Do not use the o_clk_tx_div clock until the o_p2_tx_pll_locked clock is high.

o_p2_cdr_lock 4 Output If you set the number of ports to 4, indicates that the recovered clocks from port 2 are locked to data.

Do not use the o_clk_rec_div64 or o_clk_rec_div clocks until the o_p2_cdr_lock clock is high.

o_p3_tx_pll_locked 4 Output If you set the number of ports to 4, indicates the TX PLL driving clock signal from the core port3 is locked.

Do not use the o_clk_tx_div clock until the o_p3_tx_pll_locked clock is high.

o_p3_cdr_lock 4 Output If you set the number of ports to 4, indicates that the recovered clocks from port 3 are locked to data.

Do not use the o_clk_rec_div64 or o_clk_rec_div clocks until the o_p3_cdr_lock clock is high.