Networking Interface for Open Programmable Acceleration Engine: Intel® Programmable Acceleration Card with Intel® Arria® 10 GX FPGA

ID 683532
Date 8/05/2019
Public
Document Table of Contents

3.1.4. The equalizer_tune sysfs

…/hssi_mgmt/equalizer_tune

The equalizer_tune sysfs is readable by all and writable from a privileged process (root access). It is formatted as a list of ASCII-encoded fields delimited by LF (line feed, new line) characters. Each field in the list contains a specific transceiver analog PMA setting for a specific HSSI PHY transceiver lane. There are four lanes, and each lane has a set of eight analog PMA settings. The format for each field in the list is as follows:

<hssi-phy-transceiver-lane-index>:<analog-pma-setting-index>=<analog-pma-setting>\n

The hssi-phy-transceiver-lane-index subfield specifies the HSSI PHY transceiver lane number as shown in the table below.

Table 12.  HSSI PHY Transceiver Lane Index Subfield
Supported Range of ASCII-Encoded String Values Description
"0" HSSI PHY transceiver lane 0
"1" HSSI PHY transceiver lane 1
"2" HSSI PHY transceiver lane 2
"3" HSSI PHY transceiver lane 3

The analog-pma-setting-index subfield specifies a transceiver analog PMA setting, or group of settings, for the HSSI PHY lane indicated by the hssi-phy-transceiver-lane-index subfield as shown in the table below.

Table 13.   HSSI PHY Transceiver Analog PMA Setting Index Subfield
Supported Range of ASCII-Encoded String Values Description Reference in Intel Arria 10 Transceiver PHY User Guide
"0" Receiver High Gain Mode Equalizer AC Gain Control (CTLE ACGAIN) Table Available Options in XCVR_A10_RX_ADP_CTLE_ACGAIN_4S
"1" Receiver Variable Gain Amplifier Voltage Swing Select (VGA) Table Available Options in XCVR_A10_RX_ADP_VGA_SEL
"2" Receiver High Gain Mode Equalizer DC Gain Control (CTLE DCGAIN) Table Available Options in XCVR_A10_RX_EQ_DC_GAIN_TRIM
"3" Transmitter Pre-Emphasis First Post-Tap Magnitude Table Available Options in XCVR_A10_TX_PRE_EMP_SWITCHING_CTRL_1ST_POST_TAP
"4" Transmitter Pre-Emphasis Second Post-Tap Magnitude Table Available Options in XCVR_A10_TX_PRE_EMP_SWITCHING_CTRL_2ND_POST_TAP
"5" Transmitter Pre-Emphasis First Pre-Tap Magnitude Table Available Options in XCVR_A10_TX_PRE_EMP_SWITCHING_CTRL_PRE_TAP_1T
"6" Transmitter Pre-Emphasis Second Pre-Tap Magnitude Table Available Options in XCVR_A10_TX_PRE_EMP_SWITCHING_CTRL_PRE_TAP_2T
"7" Transmitter Output Swing Level Table Available Options in XCVR_A10_TX_VOD_OUTPUT_SWING_CTRL

The ASCII-encoded string value specified by the analog-pma-setting subfield corresponds to the encoded value for the HSSI PHY transceiver analog PMA setting on the lane indicated by the hssi-phy-transceiver-lane-index:analog-pma-setting-index subfields.

The equalizer_tune sysfs reads and configures analog PMA setting value encodings for the analog-pma-setting subfield. For descriptions of those setting value encodings, refer to the Encodings sections that follow.