GTS AXI Streaming Intel® FPGA IP for PCI Express* User Guide

ID 813754
Date 8/07/2024
Public
Document Table of Contents

8.5. Indirect Register Access

The registers of virtual function (VF), HIP port and status registers can be accessed through indirect Access to CFG REG IA registers under the Control Registers.

The VF offset is the same as the parent PF offset. The following examples show accesses to the CFG REG IA register fields.

Example: Read VF2 of PF1 Type 0 Configuration Header—Command Register

  1. Write to CFG REG IA FN NUM to set function type.
    • Function Type = 3’b1
    • PF Number = 5’b1
    • VF number = 11’b10
  2. Write to CFG REG IA CTRL to initiate read operation.
    • Set Access type as read operation.
    • Register Address = 0x4
  3. Read Initiate Access bit of CFG REG IA CTRL.
    • This bit is 0 indicates read operation completes.
  4. Read data from CFG REG IA RDDATA after read operation completion indicated by Initiate Access bit = 0 in the CFG IA CTRL register.

Example: Write HIP Port Config and Status Registers—Root Port Interrupt Status

  1. Read CFG REG IA CTRL bit 0.
    • If this bit is 1, you cannot initiate read or write operation.
  2. Write to CFG REG IA FN NUM to set function type.
    • Function Type = 3’b10
    • PF Number = Don’t care
    • VF number = Don’t care
  3. Write data to CFG REG IA WRDATA.
  4. Write to CFG REG IA CTRL to initiate write operation.
    • Set Access type as write operation.
    • Set which bytes to be written.
    • Register Address = 0x1_414C.
  5. Initiate the Access bit in CFG IA CTRL register is 1 indicates the write operation in progress; This bit is 0 indicates the write operation completes.