P-Tile Avalon® Memory-mapped Intel® FPGA IP for PCI Express* User Guide

ID 683268
Date 7/14/2021
Document Table of Contents Write Data Mover Avalon® -MM Read Master and Conduit

This interface reads data from the Avalon-MM Read Master interface and writes it to the Host memory.

The wrdm_address_o value is set within the descriptor source address.

Table 34.  Write Data Mover Avalon® -MM Read Master and Conduit
Signal Name Direction Description Platform Designer Interface Name
wrdm_pfnum_o[1:0] O
Physical function number.
  • PF0: wrdm_pfnum_o[1:0] = 2'b00
  • Others: wrdm_pfnum_o[1:0] = Reserved
wrdm_waitrequest_i I

When asserted, indicates that the Avalon® -MM slave is not ready to respond to a request.

waitrequestAllowance = 4

The master can still issue 4 transfers after wrdm_waitrequest_i is asserted.

wrdm_read_o O When asserted, indicates the master is requesting a read transaction.
wrdm_address_o[63:0] O Specify the byte address regardless of the data width of the master.
wrdm_burstcount_o[3:0] O The master uses these signals to indicate the number of transfers in each burst.
wrdm_byteenable_o[63:0] O Specify the valid bytes of wrdm_writedata_o[511:0]. Each bit corresponds to a byte in wrdm_writedata_o[511:0].
wrdm_readdatavalid_i I Asserted by the slave to indicate that the wrdm_readdata_i[511:0] signals contain valid data in response to a previous read request.
wrdm_readdata_i[511:0] I Data signals for read transfers.
wrdm_response_i[1:0] I

The response signals are optional signals that carry the response status.

Note: Because the signals are shared, an interface cannot issue or accept a write response and a read response in the same clock cycle.
The following encodings are available:
  • 00: OKAY - Successful response for a transaction.
  • 01: RESERVED - Encoding is reserved.
  • 10: SLAVEERROR - Error from an endpoint slave. Indicates an unsuccessful transaction.
  • 11: DECODEERROR - Indicates an attempted access to an undefined location.
For read responses:
  • One response is sent with each readdata. A read burst length of N results in N responses. It is not valid to produce fewer responses, even in the event of an error. It is valid for the response signal values to be different for each readdata in the burst.
  • The interface must have read control signals. Pipeline support is possible with the readdatavalid signal.
  • On a read error, the corresponding readdata is a "don't care".