Arria® 10 or Cyclone® 10 GX Avalon® Memory-Mapped (Avalon-MM) DMA Interface for PCI Express* Solutions User Guide

ID 683425
Date 9/10/2024
Public
Document Table of Contents

5.1.4. RX Master Module

The RX Master module translates read and write TLPs received from the PCIe link to Avalon-MM requests for Platform Designer components connected to the interconnect. This module allows other PCIe components, including host software, to access other Avalon-MM slaves connected in the Platform Designer system.

If burst mode is not enabled, the RX Master module only supports 32-bit read or write request. All other requests received from the PCIe link are considered a violation of this device’s programming model, and are therefore handled with the PCIe Completer Abort status. You can enable burst mode for BAR2 using 32-bit addressing or BAR2 and BAR3 using 64-bit addressing. When enabled, the module supports dword, burst read, or write requests. When the Descriptor Controller is internally instantiated, the RX Master for BAR0 is used internally and not available for other uses.

Note: When you enable burst mode for BAR2, Flush reads (i.e. reads with all byte enables set to 0) are not supported.
Table 33.  RX Master Control Interface Ports for BAR Access Each BAR has one corresponding RX Master Control interface. In this table, <n> is the BAR number.

Signal Name

Direction

Description

RxmRead_<n>_o

Output

When asserted, indicates an Avalon-MM read request.

RxmWrite_<n>_o

Output

When asserted, indicates an Avalon-MM write request.

RxmAddress_<n>_o[<w>-1:0]

Output

Specifies the Avalon-MM byte address. Because all addresses are byte addresses, the meaningful bits of this address are [<w>-1:2]. Bits 1 and 0 have a value of 0. <w> can be 32 or 64.

RxmBurstCount_<n>_o[5:0]

Output

Specifies the burst count in dwords (32 bits). This optional signal is available for BAR2 when you turn on Enable burst capabilities for RXM BAR2 ports.

RxmByteEnable_<n>_o[<w>-1:0]

Output

Specifies the valid bytes of data to be written. <w> has the following values:

  • 4: for the non-bursting RX Master
  • 32: for the bursting 128-bit Avalon-MM interface
  • 64: for the bursting 256-bit Avalon-MM interface
RxmDataWrite_<n>_o[<w>-1:0]

Output

Specifies the Avalon-MM write data. <w> has the following values:

  • 32: for the non-bursting RX Master
  • 128: for the bursting 128-bit Avalon-MM interface
  • 256: for the bursting 256-bit Avalon-MM interface
RxmReadData_<n>_i[<w>-1:0]

Input

Specifies the Avalon-MM read data. <w> has the following values:

  • 32: for the non-bursting RX Master
  • 128: for the bursting 128-bit Avalon-MM interface
  • 256: for the bursting 256-bit Avalon-MM interface
RxmReadDataValid_ <n> _i[31:0]

Input

When asserted, indicates that RxmReadData_i[31:0]is valid.
RxmWaitRequest_<n>_i

Input

When asserted indicates that the control register access Avalon-MM slave port is not ready to respond.

Figure 24. RXM Master Writes to Memory in the Avalon-MM Address Space