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Merge pull request pulp-platform#279 from pulp-platform/type_widths-t…
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axi_pkg: Add functions which return channel widths
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thommythomaso authored Dec 6, 2022
2 parents af8b0ce + fe4e020 commit 15d7610
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2 changes: 2 additions & 0 deletions CHANGELOG.md
Original file line number Diff line number Diff line change
Expand Up @@ -13,6 +13,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
to compare two AXI buses on an FPGA.
- Add `axi_lite_from_mem` and `axi_from_mem` acting like SRAMs making AXI4 requests downstream.
- Add `axi_rw_join` and `axi_rw_split` to split/join AXI buses.
- Add `#_width` functions returning the width of the AXI channels.

### Changed
- `axi_demux`: Replace FIFO between AW and W channel by a register plus a counter. This prevents
Expand All @@ -21,6 +22,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
- `axi_xbar`: Add parameter `PipelineStages` to `axi_pkg::xbar_cfg_t`. This adds `axi_multicuts`
in the crossed connections in the xbar between the demuxes and muxes.
- `axi_pkg`: Add documentation to `xbar_cfg_t`.
- `axi_pkg`: Define `localparams` to define AXI type widths.

### Fixed

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105 changes: 94 additions & 11 deletions src/axi_pkg.sv
Original file line number Diff line number Diff line change
Expand Up @@ -19,26 +19,49 @@
//! AXI Package
/// Contains all necessary type definitions, constants, and generally useful functions.
package axi_pkg;
/// AXI Transaction Burst Type.
typedef logic [1:0] burst_t;
/// AXI Transaction Burst Width.
parameter int unsigned BurstWidth = 32'd2;
/// AXI Transaction Response Width.
parameter int unsigned RespWidth = 32'd2;
/// AXI Transaction Cacheability Width.
parameter int unsigned CacheWidth = 32'd4;
/// AXI Transaction Protection Width.
parameter int unsigned ProtWidth = 32'd3;
/// AXI Transaction Quality of Service Width.
parameter int unsigned QosWidth = 32'd4;
/// AXI Transaction Region Width.
parameter int unsigned RegionWidth = 32'd4;
/// AXI Transaction Length Width.
parameter int unsigned LenWidth = 32'd8;
/// AXI Transaction Size Width.
parameter int unsigned SizeWidth = 32'd3;
/// AXI Lock Width.
parameter int unsigned LockWidth = 32'd1;
/// AXI5 Atomic Operation Width.
parameter int unsigned AtopWidth = 32'd6;
/// AXI5 Non-Secure Address Identifier.
parameter int unsigned NsaidWidth = 32'd4;

/// AXI Transaction Burst Width.
typedef logic [BurstWidth-1:0] burst_t;
/// AXI Transaction Response Type.
typedef logic [1:0] resp_t;
typedef logic [RespWidth-1:0] resp_t;
/// AXI Transaction Cacheability Type.
typedef logic [3:0] cache_t;
typedef logic [CacheWidth-1:0] cache_t;
/// AXI Transaction Protection Type.
typedef logic [2:0] prot_t;
typedef logic [ProtWidth-1:0] prot_t;
/// AXI Transaction Quality of Service Type.
typedef logic [3:0] qos_t;
typedef logic [QosWidth-1:0] qos_t;
/// AXI Transaction Region Type.
typedef logic [3:0] region_t;
typedef logic [RegionWidth-1:0] region_t;
/// AXI Transaction Length Type.
typedef logic [7:0] len_t;
typedef logic [LenWidth-1:0] len_t;
/// AXI Transaction Size Type.
typedef logic [2:0] size_t;
typedef logic [SizeWidth-1:0] size_t;
/// AXI5 Atomic Operation Type.
typedef logic [5:0] atop_t; // atomic operations
typedef logic [AtopWidth-1:0] atop_t; // atomic operations
/// AXI5 Non-Secure Address Identifier.
typedef logic [3:0] nsaid_t;
typedef logic [NsaidWidth-1:0] nsaid_t;

/// In a fixed burst:
/// - The address is the same for every transfer in the burst.
Expand Down Expand Up @@ -290,6 +313,65 @@ package axi_pkg;
endcase
endfunction

/// AW Width: Returns the width of the AW channel payload
function automatic int unsigned aw_width(int unsigned addr_width, int unsigned id_width,
int unsigned user_width );
// Sum the individual bit widths of the signals
return (id_width + addr_width + LenWidth + SizeWidth + BurstWidth + LockWidth + CacheWidth +
ProtWidth + QosWidth + RegionWidth + AtopWidth + user_width );
endfunction

/// W Width: Returns the width of the W channel payload
function automatic int unsigned w_width(int unsigned data_width, int unsigned user_width );
// Sum the individual bit widths of the signals
return (data_width + data_width / 32'd8 + 32'd1 + user_width);
// ^- StrobeWidth ^- LastWidth
endfunction

/// B Width: Returns the width of the B channel payload
function automatic int unsigned b_width(int unsigned id_width, int unsigned user_width );
// Sum the individual bit widths of the signals
return (id_width + RespWidth + user_width);
endfunction

/// AR Width: Returns the width of the AR channel payload
function automatic int unsigned ar_width(int unsigned addr_width, int unsigned id_width,
int unsigned user_width );
// Sum the individual bit widths of the signals
return (id_width + addr_width + LenWidth + SizeWidth + BurstWidth + LockWidth + CacheWidth +
ProtWidth + QosWidth + RegionWidth + user_width );
endfunction

/// R Width: Returns the width of the R channel payload
function automatic int unsigned r_width(int unsigned data_width, int unsigned id_width,
int unsigned user_width );
// Sum the individual bit widths of the signals
return (id_width + data_width + RespWidth + 32'd1 + user_width);
// ^- LastWidth
endfunction

/// Request Width: Returns the width of the request channel
function automatic int unsigned req_width(int unsigned addr_width, int unsigned data_width,
int unsigned id_width, int unsigned aw_user_width,
int unsigned ar_user_width, int unsigned w_user_width );
// Sum the individual bit widths of the signals and their handshakes
// v- valids
return (aw_width(addr_width, id_width, aw_user_width) + 32'd1 +
w_width(data_width, w_user_width) + 32'd1 +
ar_width(addr_width, id_width, ar_user_width) + 32'd1 + 32'd1 + 32'd1 );
// ^- R, ^- B ready
endfunction

/// Response Width: Returns the width of the response channel
function automatic int unsigned rsp_width(int unsigned data_width, int unsigned id_width,
int unsigned r_user_width, int unsigned b_user_width );
// Sum the individual bit widths of the signals and their handshakes
// v- valids
return (r_width(data_width, id_width, r_user_width) + 32'd1 +
b_width(id_width, b_user_width) + 32'd1 + 32'd1 + 32'd1 + 32'd1);
// ^- AW, ^- AR, ^- W ready
endfunction

// ATOP[5:0]
/// - Sends a single data value with an address.
/// - The target swaps the value at the addressed location with the data value that is supplied in
Expand Down Expand Up @@ -447,4 +529,5 @@ package axi_pkg;
logic [31:0] start_addr;
logic [31:0] end_addr;
} xbar_rule_32_t;

endpackage

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