L-tile and H-tile Avalon® Memory-mapped Intel® FPGA IP for PCI Express* User Guide

ID 683667
Date 9/26/2022
Public

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Document Table of Contents

6.1.2.2. Non-Bursing Slave Module

The TX Slave module translates Avalon-MM read and write requests to PCI Express TLPs.

The slave module supports a single outstanding non-bursting request. It typically sends status updates to the host. This is a 32-bit Avalon-MM slave interface.

Table 40.  TX Slave Control

Signal Name

Direction

Description

txs_chipselect_i

Input

When asserted, indicates that this slave interface is selected. When txs_chipselect_i is deasserted, txs_read_i and txs_write_i signals are ignored.

txs_read_i

Input

When asserted, specifies a Avalon-MM Ignored when the chip select is deasserted.

txs_write_i

Input

When asserted, specifies a Avalon-MM Ignored when the chip select is deasserted.

txs_writedata_i[31:0]

Input

Specifies the Avalon-MM data for a write command.

txs_address_i[<w>-1:0]

Input

Specifies the Avalon-MM byte address for the read or write command. The width of this address bus is specified by the parameter Address width of accessible PCIe memory space.

txs_byteenable_i[3:0]

Input

Specifies the valid bytes for a write command.

txs_readdata_o[31:0]

Output

Drives the read completion data.

txs_readdatavalid_o

Output

When asserted, indicates that read data is valid.

txs_waitrequest_o

Output

When asserted, indicates that the Avalon-MM slave port is not ready to respond to a read or write request.

The non-bursting Avalon-MM slave may asserttxs_waitrequest_o during idle cycles. An Avalon-MM master may initiate a transaction when txs_waitrequest_o is asserted and wait for that signal to be deasserted.

Figure 45. Non-Bursting Slave Interface Sends Status to Host