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AXI Protocol

Advanced eXtensible Interface Protocol:

  • handshake protocol: ready-valid protocol

Channels​

Read Address​

  • arburst: burst type
  • araddr: start address
  • arlen: (# of transfers) - 1
  • arsize: bytes/transfer
  • arready (memory to host)
  • arvalid

Read Data​

  • rdata: data
  • rresp: response (failure check)
  • rlast: flag for last piece of data
  • rready (host to memory)
  • rvalid

Write Address​

  • awburst: burst type
  • awaddr: start address
  • awlen: (# of transfers) - 1
  • awsize: bytes/transfer
  • awready (memory to host)
  • awvalid

Write Data​

  • wdata: data
  • wstrb: write strobe -> write mask (1 bit mask for 1 byte data)
  • wlast: flag for last piece of data
  • wready (memory to host)
  • wvalid

Write Response​

  • bresp: response (failure check)
  • bready (host to memory)
  • bvalid

Burst​

AxBURST[1:0]Burst Type
0b00FIXED
0b01INCR
0b10WRAP
0b11Reserved

burst length = AxLEN[7:0] + 1 (up to 256 transfers in each burst)

AxSIZE[2:0]Bytes in Transfer
0b0001
0b0012
0b0104
0b0118
0b10016
0b10132
0b11064
0b111128

Read​

Read Burst Example

Write​

Write Burst Example