V-Series Transceiver PHY IP Core User Guide

ID 683171
Date 7/26/2022
Public
Document Table of Contents

11.13. Register Interface and Register Descriptions

The Avalon-MM PHY management interface provides access to the Low Latency PHY PCS and PMA registers that control the TX and RX channels, the PMA powerdown, PLL registers, and loopback modes. The following figure provides a high level view of this hardware.

Figure 58. PMA Top-Level Modules

The following table describes the signals in the PHY Management interface:

Table 159.  Avalon-MM PHY Management Interface 

Signal Name

Direction

Description

phy_mgmt_clk

Input

Avalon-MM clock input. There is no frequency restriction for the phy_mgmt_clk; however, if you plan to use the same clock for the PHY management interface and transceiver reconfiguration, you must restrict the frequency range of phy_mgmt_clk to 100–150 MHz to meet the specification for the transceiver reconfiguration clock.

phy_mgmt_clk_reset

Input

Global reset signal. This signal is active high and level sensitive. This is an asynchronous signal.

phy_mgmtaddress[8:0]

Input

9-bit Avalon-MM address.

phy_mgmt_writedata[31:0]

Input

Input data.

phy_mgmt_readdata[31:0]

Output

Output data.

phy_mgmt_write

Input

Write signal.

phy_mgmt_read

Input

Read signal.

For more information about the Avalon-MM and Avalon-ST protocols, including timing diagrams, refer to the Avalon Interface Specifications .

The following table describes the registers that you can access over the PHY Management Interface using word addresses and a 32-bit embedded processor. The automatic reset controller automatically performs the required reset sequence. After this reset sequence completes, you can manually initiate TX or RX resets using the reset_control control register. You can also specify the clock data recovery (CDR) circuit to lock to the incoming data or the reference clock using the pma_rx_set_locktodata and pma_rx_set_locktoref registers.

Note: Writing to reserved or undefined register addresses may have undefined side effects.
Table 160.  Low Latency PHY IP Core Registers  (Part 1 of 2)

Word Addr

Bits

R/W

Register Name

Description

Reset Control Registers–Automatic Reset Controller

0x041

[31:0]

RW

reset_ch_bitmask

Reset controller channel bitmask for digital resets. The default value is all 1s. Channel <n> can be reset when bit <n> = 1.

0x042

[1:0]

W

reset_control (write)

Writing a 1 to bit 0 initiates a TX digital reset using the reset controller module. The reset affects channels enabled in the reset_ch_bitmask. Writing a 1 to bit 1 initiates a RX digital reset of channels enabled in the reset_ch_bitmask.

R

reset_status (read)

Reading bit 0 returns the status of the reset controller TX ready bit. Reading bit 1 returns the status of the reset controller RX ready bit.

0x061

[31:0]

RW

phy_serial_loopback_

Writing a 1 to channel < n > puts channel < n > in serial loopback mode. For information about pre or postCDR serial loopback modes, refer to Loopback Modes.

PMA Control and Status Registers

0x063

[31:0]

R

pma_rx_signaldetect

When channel <n> =1, indicates that receive circuit for channel <n> senses the specified voltage exists at the RX input buffer.

0x064

[31:0]

RW

pma_rx_set_locktodata

When set, programs the RX CDR PLL to lock to the incoming data. Bit <n> corresponds to channel <n>.

0x065

[31:0]

RW

pma_rx_set_locktoref

When set, programs the RX CDR PLL to lock to the reference clock. Bit <n> corresponds to channel <n>.

0x066

[31:0]

RO

pma_rx_is_lockedtodata

When asserted, indicates that the RX CDR PLL is locked to the RX data, and that the RX CDR has changed from LTR to LTD mode. Bit <n> corresponds to channel <n>.

0x067

[31:0]

RO

pma_rx_is_lockedtoref

When asserted, indicates that the RX CDR PLL is locked to the reference clock. Bit <n> corresponds to channel <n>.