Verilog AXI Components Readme

For more information and updates: http://alexforencich.com/wiki/en/verilog/axi/start

GitHub repository: https://github.com/alexforencich/verilog-axi

Introduction

Collection of AXI4 and AXI4 lite bus components. Most components are fully parametrizable in interface widths. Includes full MyHDL testbench with intelligent bus cosimulation endpoints.

Documentation

axi_adapter module

AXI width adapter module with parametrizable data and address interface widths. Supports INCR burst types and narrow bursts. Wrapper for axi_adapter_rd and axi_adapter_wr.

axi_adapter_rd module

AXI width adapter module with parametrizable data and address interface widths. Supports INCR burst types and narrow bursts.

axi_adapter_wr module

AXI width adapter module with parametrizable data and address interface widths. Supports INCR burst types and narrow bursts.

axi_axil_adapter module

AXI to AXI lite converter and width adapter module with parametrizable data and address interface widths. Supports INCR burst types and narrow bursts. Wrapper for axi_axil_adapter_rd and axi_axil_adapter_wr.

axi_axil_adapter_rd module

AXI to AXI lite converter and width adapter module with parametrizable data and address interface widths. Supports INCR burst types and narrow bursts.

axi_axil_adapter_wr module

AXI to AXI lite converter and width adapter module with parametrizable data and address interface widths. Supports INCR burst types and narrow bursts.

axi_cdma module

AXI to AXI DMA engine with parametrizable data and address interface widths. Generates full-width INCR bursts only, with parametrizable maximum burst length. Supports unaligned transfers, which can be disabled via parameter to save on resource consumption.

axi_cdma_desc_mux module

Descriptor multiplexer/demultiplexer for AXI CDMA module. Enables sharing the AXI CDMA module between multiple request sources, interleaving requests and distributing responses.

axi_crossbar module

AXI nonblocking crossbar interconnect with parametrizable data and address interface widths and master and slave interface counts. Supports all burst types. Fully nonblocking with completely separate read and write paths; ID based transaction ordering protection logic; and per-port address decode, admission control, and decode error handling. Wrapper for axi_crossbar_rd and axi_crossbar_wr.

axi_crossbar_addr module

Address decode and admission control module for AXI nonblocking crossbar interconnect.

axi_crossbar_rd module

AXI nonblocking crossbar interconnect with parametrizable data and address interface widths and master and slave interface counts. Read interface only. Supports all burst types. Fully nonblocking with completely separate read and write paths; ID based transaction ordering protection logic; and per-port address decode, admission control, and decode error handling.

axi_crossbar_wr module

AXI nonblocking crossbar interconnect with parametrizable data and address interface widths and master and slave interface counts. Write interface only. Supports all burst types. Fully nonblocking with completely separate read and write paths; ID based transaction ordering protection logic; and per-port address decode, admission control, and decode error handling.

axi_dma module

AXI to AXI stream DMA engine with parametrizable data and address interface widths. Generates full-width INCR bursts only, with parametrizable maximum burst length. Supports unaligned transfers, which can be disabled via parameter to save on resource consumption. Wrapper for axi_dma_rd and axi_dma_wr.

axi_dma_desc_mux module

Descriptor multiplexer/demultiplexer for AXI DMA module. Enables sharing the AXI DMA module between multiple request sources, interleaving requests and distributing responses.

axi_dma_rd module

axi_dma_wr module

AXI stream to AXI DMA engine with parametrizable data and address interface widths. Generates full-width INCR bursts only, with parametrizable maximum burst length. Supports unaligned transfers, which can be disabled via parameter to save on resource consumption.

axi_fifo module

AXI FIFO with parametrizable data and address interface widths. Supports all burst types. Optionally can delay the address channel until either the write data is completely shifted into the FIFO or the read data FIFO has enough capacity to fit the whole burst. Wrapper for axi_fifo_rd and axi_fifo_wr.

axi_fifo_rd module

AXI FIFO with parametrizable data and address interface widths. AR and R channels only. Supports all burst types. Optionally can delay the address channel until either the read data FIFO is empty or has enough capacity to fit the whole burst.

axi_fifo_wr module

AXI FIFO with parametrizable data and address interface widths. WR, W, and B channels only. Supports all burst types. Optionally can delay the address channel until the write data is shifted completely into the write data FIFO, or the current burst completely fills the write data FIFO.

axi_interconnect module

AXI shared interconnect with parametrizable data and address interface widths and master and slave interface counts. Supports all burst types. Small in area, but does not support concurrent operations.

axi_ram module

AXI RAM with parametrizable data and address interface widths. Supports FIXED and INCR burst types as well as narrow bursts.

axi_register module

AXI register with parametrizable data and address interface widths. Supports all burst types. Inserts simple buffers or skid buffers into all channels. Channel register types can be individually changed or bypassed. Wrapper for axi_register_rd and axi_register_wr.

axi_register_rd module

AXI register with parametrizable data and address interface widths. AR and R channels only. Supports all burst types. Inserts simple buffers or skid buffers into all channels. Channel register types can be individually changed or bypassed.

axi_register_wr module

AXI register with parametrizable data and address interface widths. WR, W, and B channels only. Supports all burst types. Inserts simple buffers or skid buffers into all channels. Channel register types can be individually changed or bypassed.

axil_adapter module

AXI lite width adapter module with parametrizable data and address interface widths. Wrapper for axi_adapter_rd and axi_adapter_wr.

axil_adapter_rd module

AXI lite width adapter module with parametrizable data and address interface widths.

axil_adapter_wr module

AXI lite width adapter module with parametrizable data and address interface widths.

axil_cdc module

AXI lite clock domain crossing module with parametrizable data and address interface widths. Wrapper for axi_cdc_rd and axi_cdc_wr.

axil_cdc_rd module

AXI lite clock domain crossing module with parametrizable data and address interface widths.

axil_cdc_wr module

AXI lite clock domain crossing module with parametrizable data and address interface widths.

axil_interconnect module

AXI lite shared interconnect with parametrizable data and address interface widths and master and slave interface counts. Small in area, but does not support concurrent operations.

axil_ram module

AXI lite RAM with parametrizable data and address interface widths.

axil_register module

AXI lite register with parametrizable data and address interface widths. Inserts skid buffers into all channels. Channel registers can be individually bypassed. Wrapper for axil_register_rd and axil_register_wr.

axil_register_rd module

AXI lite register with parametrizable data and address interface widths. AR and R channels only. Inserts simple buffers into all channels. Channel registers can be individually bypassed.

axil_register_wr module

AXI lite register with parametrizable data and address interface widths. WR, W, and B channels only. Inserts simple buffers into all channels. Channel registers can be individually bypassed.

Common signals

awid     : Write address ID
awaddr   : Write address
awlen    : Write burst length
awsize   : Write burst size
awburst  : Write burst type
awlock   : Write locking
awcache  : Write cache handling
awprot   : Write protection level
awqos    : Write QoS setting
awregion : Write region
awuser   : Write user sideband signal
awvalid  : Write address valid
awready  : Write address ready (from slave)
wdata    : Write data
wstrb    : Write data strobe (byte select)
wlast    : Write data last transfer in burst
wuser    : Write data user sideband signal
wvalid   : Write data valid
wready   : Write data ready (from slave)
bid      : Write response ID
bresp    : Write response
buser    : Write response user sideband signal
bvalid   : Write response valid
bready   : Write response ready (from master)
arid     : Read address ID
araddr   : Read address
arlen    : Read burst length
arsize   : Read burst size
arburst  : Read burst type
arlock   : Read locking
arcache  : Read cache handling
arprot   : Read protection level
arqos    : Read QoS setting
arregion : Read region
aruser   : Read user sideband signal
arvalid  : Read address valid
arready  : Read address ready (from slave)
rid      : Read data ID
rdata    : Read data
rresp    : Read response
rlast    : Read data last transfer in burst
ruser    : Read data user sideband signal
rvalid   : Read response valid
rready   : Read response ready (from master)

Common parameters

ADDR_WIDTH           : width of awaddr and araddr signals
DATA_WIDTH           : width of wdata and rdata signals
STRB_WIDTH           : width of wstrb signal
ID_WIDTH             : width of *id signals
AWUSER_ENABLE        : enable awuser signal
AWUSER_WIDTH         : width of awuser signal
WUSER_ENABLE         : enable wuser signal
WUSER_WIDTH          : width of wuser signal
BUSER_ENABLE         : enable buser signal
BUSER_WIDTH          : width of buser signal
ARUSER_ENABLE        : enable aruser signal
ARUSER_WIDTH         : width of aruser signal
RUSER_ENABLE         : enable ruser signal
RUSER_WIDTH          : width of ruser signal

Source Files

rtl/arbiter.v                   : Parametrizable arbiter
rtl/axi_adapter.v               : AXI lite width converter
rtl/axi_adapter_rd.v            : AXI lite width converter (read)
rtl/axi_adapter_wr.v            : AXI lite width converter (write)
rtl/axi_axil_adapter.v          : AXI to AXI lite converter
rtl/axi_axil_adapter_rd.v       : AXI to AXI lite converter (read)
rtl/axi_axil_adapter_wr.v       : AXI to AXI lite converter (write)
rtl/axi_cdma.v                  : AXI central DMA engine
rtl/axi_cdma_desc_mux.v         : AXI CDMA descriptor mux
rtl/axi_crossbar.v              : AXI nonblocking crossbar interconnect
rtl/axi_crossbar_addr.v         : AXI crossbar address module
rtl/axi_crossbar_rd.v           : AXI crossbar read module
rtl/axi_crossbar_wr.v           : AXI crossbar write module
rtl/axi_dma.v                   : AXI DMA engine
rtl/axi_dma_desc_mux.v          : AXI DMA descriptor mux
rtl/axi_dma_rd.v                : AXI DMA engine (read)
rtl/axi_dma_wr.v                : AXI DMA engine (write)
rtl/axi_fifo.v                  : AXI FIFO
rtl/axi_fifo_rd.v               : AXI FIFO (read)
rtl/axi_fifo_wr.v               : AXI FIFO (write)
rtl/axi_interconnect.v          : AXI shared interconnect
rtl/axi_ram.v                   : AXI RAM
rtl/axi_register.v              : AXI register
rtl/axi_register_rd.v           : AXI register (read)
rtl/axi_register_wr.v           : AXI register (write)
rtl/axil_adapter.v              : AXI lite width converter
rtl/axil_adapter_rd.v           : AXI lite width converter (read)
rtl/axil_adapter_wr.v           : AXI lite width converter (write)
rtl/axil_cdc.v                  : AXI lite CDC
rtl/axil_cdc_rd.v               : AXI lite CDC (read)
rtl/axil_cdc_wr.v               : AXI lite CDC (write)
rtl/axil_interconnect.v         : AXI lite shared interconnect
rtl/axil_ram.v                  : AXI lite RAM
rtl/axil_register.v             : AXI lite register
rtl/axil_register_rd.v          : AXI lite register (read)
rtl/axil_register_wr.v          : AXI lite register (write)
rtl/priority_encoder.v          : Parametrizable priority encoder

AXI4-Lite Interface Example

Write

            ___     ___     ___     ___     ___    
clk     ___/   \___/   \___/   \___/   \___/   \___
            _______
awid    XXXX_ID____XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
            _______
awaddr  XXXX_ADDR__XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
            _______
awlen   XXXX_00____XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
            _______
awsize  XXXX_0_____XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
            _______
awburst XXXX_0_____XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
            _______
awprot  XXXX_PROT__XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
            _______
awvalid ___/       \_______________________________
        ___________         _______________________
awready            \_______/
            _______________
wdata   XXXX_DATA__________XXXXXXXXXXXXXXXXXXXXXXXX
            _______________
wstrb   XXXX_STRB__________XXXXXXXXXXXXXXXXXXXXXXXX
            _______________
wvalid  ___/               \_______________________
                    _______
wready  ___________/       \_______________________
                                    _______
bid     XXXXXXXXXXXXXXXXXXXXXXXXXXXX_ID____XXXXXXXX
                                    _______
bresp   XXXXXXXXXXXXXXXXXXXXXXXXXXXX_RESP__XXXXXXXX
                                    _______
bvalid  ___________________________/       \_______
        ___________________________________________
bready

Read

            ___     ___     ___     ___     ___    
clk     ___/   \___/   \___/   \___/   \___/   \___
            _______
arid    XXXX_ID____XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
            _______
araddr  XXXX_ADDR__XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
            _______
arlen   XXXX_00____XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
            _______
arsize  XXXX_0_____XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
            _______
arburst XXXX_0_____XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
            _______
arprot  XXXX_PROT__XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
            _______
arvalid ___/       \_______________________________
        ___________________________________________
arready
                                    _______
rid     XXXXXXXXXXXXXXXXXXXXXXXXXXXX_ID____XXXXXXXX
                                    _______
rdata   XXXXXXXXXXXXXXXXXXXXXXXXXXXX_DATA__XXXXXXXX
                                    _______
rresp   XXXXXXXXXXXXXXXXXXXXXXXXXXXX_RESP__XXXXXXXX
                                    _______
rvalid  ___________________________/       \_______
        ___________________________________________
rready

Testing

Running the included testbenches requires MyHDL and Icarus Verilog. Make sure that myhdl.vpi is installed properly for cosimulation to work correctly. The testbenches can be run with a Python test runner like nose or py.test, or the individual test scripts can be run with python directly.

Testbench Files

tb/axi.py            : MyHDL AXI4 master and memory BFM
tb/axil.py           : MyHDL AXI4 lite master and memory BFM