Multi Channel DMA Intel® FPGA IP for PCI Express User Guide

ID 683821
Date 4/11/2023

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4.6. Bursting Avalon-MM Slave (BAS) Interface

Table 45.  BAS Signals
Signal Name I/O Type Description
bas_vfactive_i Input When asserted, this signal indicates AVMM transaction is targeting a virtual function

H-Tile: bas_pfnum_i[1:0]

P-Tile and F-Tile and R-Tile: bas_pfnum_i[2:0]

Input Specifies a target PF number
bas_vfnum_i[10:0] Input Specifies a target VF number

H-Tile: bas_address_i [63:0]

P-Tile, F-Tile and R-Tile : bas_address_i[<n>-1:0]


Specify the byte address regardless of the data width of the master.

The Bursting Slave's addresses must be aligned to the width of the data bus. For example, if the data width is 64B, the addresses must align to 64B.

In P/F/R-Tile End Point mode the BAS address width <n> is always 64.

In P/F/R-Tile Root Port mode, if ATT is enabled then <n> : (ATT Table Address Width) + (ATT Window Address Width), else <n> : 64

x16: bas_byteenable_i[63:0]

x8: bas_byteenable_i[31:0]


Enables one or more specific bytes of write data during transfers on interfaces. For x16, each bas_byteenable bit corresponds to a byte in bas_writedata_i[511:0].

For single-cycle read bursts and for all write bursts, all contiguous sets of enabled bytes are supported.

For burst read transactions, the bas_byteenable_i[63:0] must be 64'hFFFF_FFFF_FFFF_FF

x16: bas_burstcount_i[3:0]

x8: bas_burstcount_i[4:0]

Input Used by a bursting master to indicate the number of transfers in each burst.
bas_read_i Input Asserted to indicate a read transfer.

x16: bas_readdata_o[511:0]

x8: bas_readdata_o[255:0]

Output Read data to the user logic in response to a read transfer
bas_readdatavalid_o Output When asserted, indicates that the readdata signal contains valid data. For a read burst with burstcount value <n>, the readdatavalid signal must be asserted <n> times, once for each readdata item.
bas_write_i Input Asserted to indicate a write transfer

x16: bas_writedata_i[511:0]

x8: bas_writedata_i[255:0]

Input Data for write transfers
bas_waitrequest_o Output

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

waitrequestAllowance = 0

The master cannot issue any transfer after bas_waitrequest_o is asserted.

bas_response_o[1:0] Output
Carries the response status:
  • 00: OKAY. Successful response for a transaction.
  • 01: RESERVED. Encoding is reserved.
  • 10: SLAVEERROR. Error from an endpoint agent. Indicates an unsuccessful transaction.
  • 11: DECODEERROR. Indicates attempted access to an undefined location.