User guide

You can use a fPLL or a CMU PLL to generate the clock for the TX PMA for the 1G data rate. For the 10G
data rate, you can use the ATX PLL or the CMU PLL. For the 1G data rate, the frequency of the TX and
RX clocks is 125 MHz, which is 1/8 of the MAC data rate. For the 10G data rate, the frequency of TX and
RX clocks is 156.25 MHz, 1/64 of the MAC data rate. You can generate the 156.25 MHz clock directly by
using a fPLL, or you can divide the clock from TX PLL by 33. The 1G/10GbE PHY does not support
bonded clocks.
The following figure provides an overview of the clocking for this core.
Figure 2-59: Clocks for Standard and 10G PCS and TX PLLs
xgmii_rx_clk
156.25 MHz
xgmii_tx_clk
156.25 MHz
1GbE/10GbE PHY
Standard RX PCS
TX PMA
tx_coreclkin_1g
125 MHz
RX PMA
TX PLL
TX PLL
10
rx_pld_clk
rx_pma_clk
TX serial data
8+1
GMII TX
Data & Control
XGMII TX Data & Control
RX data
161.1 MHz (2)
red = datapath includes FEC
10
TX data
40
64
TX data
serial data
pll_ref_clk_10g
644.53125 MHz
or
322.265625 MHz
pll_ref_clk_1g
125 MHz
Standard TX PCS
tx_pld_clk tx_pma_clk
GMII RX
Data & Control
64 + 8
64 + 8
XGMII RX Data & Control
recovered clk
257.8125 MHz (1)
rx_coreclkin_1g
125 MHz
Enhanced RX PCS
rx_pld_clk rx_pma_clk
Enhanced TX PCS
tx_pld_clk tx_pma_clk
fractional
PLL
(instantiate
separately)
SGMII
PCS
SGMII
PCS
tx_pld_clk
8+1
60
40
64 + 8
64 + 8
125 MHz
Notes:
1. 257.8125 MHz is for 10GbE.
2. 161.1 MHz is the FEC clock for 10GbE.
The following table describes the clock and reset signals.
Table 2-119: Clock and Reset Signals
Signal Name Direction Description
tx_serial_clk_10g Input High speed clock from the 10G PLL to drive 10G
PHY TX PMA. The frequency of this clock is
5.15625 GHz.
tx_serial_clk_1g Input The clock from the external 1G PLL to drive the TX
high speed serial interface (HSSI) circuits.
Connected to the tx_serial_clk[1] input of the
native PHY.
rx_cdr_ref_clk_10g Input 10G PHY RX PLL reference clock. This clock
frequency can be 644.53125 MHz or 322.2656 MHz.
2-168
Clock and Reset Interfaces
UG-01143
2015.05.11
Altera Corporation
Implementing Protocols in Arria 10 Transceivers
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