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corundum/rtl/axil_interconnect.v
2019-07-25 16:33:27 -07:00

490 lines
20 KiB
Verilog

/*
Copyright (c) 2018 Alex Forencich
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.
*/
// Language: Verilog 2001
`timescale 1ns / 1ps
/*
* AXI4 lite interconnect
*/
module axil_interconnect #
(
// Number of AXI inputs (slave interfaces)
parameter S_COUNT = 4,
// Number of AXI outputs (master interfaces)
parameter M_COUNT = 4,
// Width of data bus in bits
parameter DATA_WIDTH = 32,
// Width of address bus in bits
parameter ADDR_WIDTH = 32,
// Width of wstrb (width of data bus in words)
parameter STRB_WIDTH = (DATA_WIDTH/8),
// Number of regions per master interface
parameter M_REGIONS = 1,
// Master interface base addresses
// M_COUNT concatenated fields of M_REGIONS concatenated fields of ADDR_WIDTH bits
parameter M_BASE_ADDR = {32'h03000000, 32'h02000000, 32'h01000000, 32'h00000000},
// Master interface address widths
// M_COUNT concatenated fields of M_REGIONS concatenated fields of 32 bits
parameter M_ADDR_WIDTH = {M_COUNT{{M_REGIONS{32'd24}}}},
// Read connections between interfaces
// M_COUNT concatenated fields of S_COUNT bits
parameter M_CONNECT_READ = {M_COUNT{{S_COUNT{1'b1}}}},
// Write connections between interfaces
// M_COUNT concatenated fields of S_COUNT bits
parameter M_CONNECT_WRITE = {M_COUNT{{S_COUNT{1'b1}}}},
// Secure master (fail operations based on awprot/arprot)
// M_COUNT bits
parameter M_SECURE = {M_COUNT{1'b0}}
)
(
input wire clk,
input wire rst,
/*
* AXI lite slave interfaces
*/
input wire [S_COUNT*ADDR_WIDTH-1:0] s_axil_awaddr,
input wire [S_COUNT*3-1:0] s_axil_awprot,
input wire [S_COUNT-1:0] s_axil_awvalid,
output wire [S_COUNT-1:0] s_axil_awready,
input wire [S_COUNT*DATA_WIDTH-1:0] s_axil_wdata,
input wire [S_COUNT*STRB_WIDTH-1:0] s_axil_wstrb,
input wire [S_COUNT-1:0] s_axil_wvalid,
output wire [S_COUNT-1:0] s_axil_wready,
output wire [S_COUNT*2-1:0] s_axil_bresp,
output wire [S_COUNT-1:0] s_axil_bvalid,
input wire [S_COUNT-1:0] s_axil_bready,
input wire [S_COUNT*ADDR_WIDTH-1:0] s_axil_araddr,
input wire [S_COUNT*3-1:0] s_axil_arprot,
input wire [S_COUNT-1:0] s_axil_arvalid,
output wire [S_COUNT-1:0] s_axil_arready,
output wire [S_COUNT*DATA_WIDTH-1:0] s_axil_rdata,
output wire [S_COUNT*2-1:0] s_axil_rresp,
output wire [S_COUNT-1:0] s_axil_rvalid,
input wire [S_COUNT-1:0] s_axil_rready,
/*
* AXI lite master interfaces
*/
output wire [M_COUNT*ADDR_WIDTH-1:0] m_axil_awaddr,
output wire [M_COUNT*3-1:0] m_axil_awprot,
output wire [M_COUNT-1:0] m_axil_awvalid,
input wire [M_COUNT-1:0] m_axil_awready,
output wire [M_COUNT*DATA_WIDTH-1:0] m_axil_wdata,
output wire [M_COUNT*STRB_WIDTH-1:0] m_axil_wstrb,
output wire [M_COUNT-1:0] m_axil_wvalid,
input wire [M_COUNT-1:0] m_axil_wready,
input wire [M_COUNT*2-1:0] m_axil_bresp,
input wire [M_COUNT-1:0] m_axil_bvalid,
output wire [M_COUNT-1:0] m_axil_bready,
output wire [M_COUNT*ADDR_WIDTH-1:0] m_axil_araddr,
output wire [M_COUNT*3-1:0] m_axil_arprot,
output wire [M_COUNT-1:0] m_axil_arvalid,
input wire [M_COUNT-1:0] m_axil_arready,
input wire [M_COUNT*DATA_WIDTH-1:0] m_axil_rdata,
input wire [M_COUNT*2-1:0] m_axil_rresp,
input wire [M_COUNT-1:0] m_axil_rvalid,
output wire [M_COUNT-1:0] m_axil_rready
);
parameter CL_S_COUNT = $clog2(S_COUNT);
parameter CL_M_COUNT = $clog2(M_COUNT);
integer i, j;
// check configuration
initial begin
for (i = 0; i < M_COUNT*M_REGIONS; i = i + 1) begin
if (M_ADDR_WIDTH[i*32 +: 32] && (M_ADDR_WIDTH[i*32 +: 32] < 0 || M_ADDR_WIDTH[i*32 +: 32] > ADDR_WIDTH)) begin
$error("Error: address width out of range (instance %m)");
$finish;
end
end
for (i = 0; i < M_COUNT*M_REGIONS; i = i + 1) begin
for (j = i+1; j < M_COUNT*M_REGIONS; j = j + 1) begin
if (M_ADDR_WIDTH[i*32 +: 32] && M_ADDR_WIDTH[j*32 +: 32]) begin
if (((M_BASE_ADDR[i*ADDR_WIDTH +: ADDR_WIDTH] & ({ADDR_WIDTH{1'b1}} << M_ADDR_WIDTH[i*32 +: 32])) <= (M_BASE_ADDR[j*ADDR_WIDTH +: ADDR_WIDTH] | ({ADDR_WIDTH{1'b1}} >> (ADDR_WIDTH - M_ADDR_WIDTH[j*32 +: 32])))) && ((M_BASE_ADDR[j*ADDR_WIDTH +: ADDR_WIDTH] & ({ADDR_WIDTH{1'b1}} << M_ADDR_WIDTH[j*32 +: 32])) <= (M_BASE_ADDR[i*ADDR_WIDTH +: ADDR_WIDTH] | ({ADDR_WIDTH{1'b1}} >> (ADDR_WIDTH - M_ADDR_WIDTH[i*32 +: 32]))))) begin
$display("%d: %08x / %02d -- %08x-%08x", i, M_BASE_ADDR[i*ADDR_WIDTH +: ADDR_WIDTH], M_ADDR_WIDTH[i*32 +: 32], M_BASE_ADDR[i*ADDR_WIDTH +: ADDR_WIDTH] & ({ADDR_WIDTH{1'b1}} << M_ADDR_WIDTH[i*32 +: 32]), M_BASE_ADDR[i*ADDR_WIDTH +: ADDR_WIDTH] | ({ADDR_WIDTH{1'b1}} >> (ADDR_WIDTH - M_ADDR_WIDTH[i*32 +: 32])));
$display("%d: %08x / %02d -- %08x-%08x", j, M_BASE_ADDR[j*ADDR_WIDTH +: ADDR_WIDTH], M_ADDR_WIDTH[j*32 +: 32], M_BASE_ADDR[j*ADDR_WIDTH +: ADDR_WIDTH] & ({ADDR_WIDTH{1'b1}} << M_ADDR_WIDTH[j*32 +: 32]), M_BASE_ADDR[j*ADDR_WIDTH +: ADDR_WIDTH] | ({ADDR_WIDTH{1'b1}} >> (ADDR_WIDTH - M_ADDR_WIDTH[j*32 +: 32])));
$error("Error: address ranges overlap (instance %m)");
$finish;
end
end
end
end
end
localparam [2:0]
STATE_IDLE = 3'd0,
STATE_DECODE = 3'd1,
STATE_WRITE = 3'd2,
STATE_WRITE_RESP = 3'd3,
STATE_WRITE_DROP = 3'd4,
STATE_READ = 3'd5,
STATE_WAIT_IDLE = 3'd6;
reg [2:0] state_reg = STATE_IDLE, state_next;
reg match;
reg [CL_M_COUNT-1:0] m_select_reg = 2'd0, m_select_next;
reg [ADDR_WIDTH-1:0] axil_addr_reg = {ADDR_WIDTH{1'b0}}, axil_addr_next;
reg axil_addr_valid_reg = 1'b0, axil_addr_valid_next;
reg [2:0] axil_prot_reg = 3'b000, axil_prot_next;
reg [DATA_WIDTH-1:0] axil_data_reg = {DATA_WIDTH{1'b0}}, axil_data_next;
reg [STRB_WIDTH-1:0] axil_wstrb_reg = {STRB_WIDTH{1'b0}}, axil_wstrb_next;
reg [1:0] axil_resp_reg = 2'b00, axil_resp_next;
reg [S_COUNT-1:0] s_axil_awready_reg = 0, s_axil_awready_next;
reg [S_COUNT-1:0] s_axil_wready_reg = 0, s_axil_wready_next;
reg [S_COUNT-1:0] s_axil_bvalid_reg = 0, s_axil_bvalid_next;
reg [S_COUNT-1:0] s_axil_arready_reg = 0, s_axil_arready_next;
reg [S_COUNT-1:0] s_axil_rvalid_reg = 0, s_axil_rvalid_next;
reg [M_COUNT-1:0] m_axil_awvalid_reg = 0, m_axil_awvalid_next;
reg [M_COUNT-1:0] m_axil_wvalid_reg = 0, m_axil_wvalid_next;
reg [M_COUNT-1:0] m_axil_bready_reg = 0, m_axil_bready_next;
reg [M_COUNT-1:0] m_axil_arvalid_reg = 0, m_axil_arvalid_next;
reg [M_COUNT-1:0] m_axil_rready_reg = 0, m_axil_rready_next;
assign s_axil_awready = s_axil_awready_reg;
assign s_axil_wready = s_axil_wready_reg;
assign s_axil_bresp = {S_COUNT{axil_resp_reg}};
assign s_axil_bvalid = s_axil_bvalid_reg;
assign s_axil_arready = s_axil_arready_reg;
assign s_axil_rdata = {S_COUNT{axil_data_reg}};
assign s_axil_rresp = {S_COUNT{axil_resp_reg}};
assign s_axil_rvalid = s_axil_rvalid_reg;
assign m_axil_awaddr = {M_COUNT{axil_addr_reg}};
assign m_axil_awprot = {M_COUNT{axil_prot_reg}};
assign m_axil_awvalid = m_axil_awvalid_reg;
assign m_axil_wdata = {M_COUNT{axil_data_reg}};
assign m_axil_wstrb = {M_COUNT{axil_wstrb_reg}};
assign m_axil_wvalid = m_axil_wvalid_reg;
assign m_axil_bready = m_axil_bready_reg;
assign m_axil_araddr = {M_COUNT{axil_addr_reg}};
assign m_axil_arprot = {M_COUNT{axil_prot_reg}};
assign m_axil_arvalid = m_axil_arvalid_reg;
assign m_axil_rready = m_axil_rready_reg;
// slave side mux
wire [(CL_S_COUNT > 0 ? CL_S_COUNT-1 : 0):0] s_select;
wire [ADDR_WIDTH-1:0] current_s_axil_awaddr = s_axil_awaddr[s_select*ADDR_WIDTH +: ADDR_WIDTH];
wire [2:0] current_s_axil_awprot = s_axil_awprot[s_select*3 +: 3];
wire current_s_axil_awvalid = s_axil_awvalid[s_select];
wire current_s_axil_awready = s_axil_awready[s_select];
wire [DATA_WIDTH-1:0] current_s_axil_wdata = s_axil_wdata[s_select*DATA_WIDTH +: DATA_WIDTH];
wire [STRB_WIDTH-1:0] current_s_axil_wstrb = s_axil_wstrb[s_select*STRB_WIDTH +: STRB_WIDTH];
wire current_s_axil_wvalid = s_axil_wvalid[s_select];
wire current_s_axil_wready = s_axil_wready[s_select];
wire [1:0] current_s_axil_bresp = s_axil_bresp[s_select*2 +: 2];
wire current_s_axil_bvalid = s_axil_bvalid[s_select];
wire current_s_axil_bready = s_axil_bready[s_select];
wire [ADDR_WIDTH-1:0] current_s_axil_araddr = s_axil_araddr[s_select*ADDR_WIDTH +: ADDR_WIDTH];
wire [2:0] current_s_axil_arprot = s_axil_arprot[s_select*3 +: 3];
wire current_s_axil_arvalid = s_axil_arvalid[s_select];
wire current_s_axil_arready = s_axil_arready[s_select];
wire [DATA_WIDTH-1:0] current_s_axil_rdata = s_axil_rdata[s_select*DATA_WIDTH +: DATA_WIDTH];
wire [1:0] current_s_axil_rresp = s_axil_rresp[s_select*2 +: 2];
wire current_s_axil_rvalid = s_axil_rvalid[s_select];
wire current_s_axil_rready = s_axil_rready[s_select];
// master side mux
wire [ADDR_WIDTH-1:0] current_m_axil_awaddr = m_axil_awaddr[m_select_reg*ADDR_WIDTH +: ADDR_WIDTH];
wire [2:0] current_m_axil_awprot = m_axil_awprot[m_select_reg*3 +: 3];
wire current_m_axil_awvalid = m_axil_awvalid[m_select_reg];
wire current_m_axil_awready = m_axil_awready[m_select_reg];
wire [DATA_WIDTH-1:0] current_m_axil_wdata = m_axil_wdata[m_select_reg*DATA_WIDTH +: DATA_WIDTH];
wire [STRB_WIDTH-1:0] current_m_axil_wstrb = m_axil_wstrb[m_select_reg*STRB_WIDTH +: STRB_WIDTH];
wire current_m_axil_wvalid = m_axil_wvalid[m_select_reg];
wire current_m_axil_wready = m_axil_wready[m_select_reg];
wire [1:0] current_m_axil_bresp = m_axil_bresp[m_select_reg*2 +: 2];
wire current_m_axil_bvalid = m_axil_bvalid[m_select_reg];
wire current_m_axil_bready = m_axil_bready[m_select_reg];
wire [ADDR_WIDTH-1:0] current_m_axil_araddr = m_axil_araddr[m_select_reg*ADDR_WIDTH +: ADDR_WIDTH];
wire [2:0] current_m_axil_arprot = m_axil_arprot[m_select_reg*3 +: 3];
wire current_m_axil_arvalid = m_axil_arvalid[m_select_reg];
wire current_m_axil_arready = m_axil_arready[m_select_reg];
wire [DATA_WIDTH-1:0] current_m_axil_rdata = m_axil_rdata[m_select_reg*DATA_WIDTH +: DATA_WIDTH];
wire [1:0] current_m_axil_rresp = m_axil_rresp[m_select_reg*2 +: 2];
wire current_m_axil_rvalid = m_axil_rvalid[m_select_reg];
wire current_m_axil_rready = m_axil_rready[m_select_reg];
// arbiter instance
wire [S_COUNT*2-1:0] request;
wire [S_COUNT*2-1:0] acknowledge;
wire [S_COUNT*2-1:0] grant;
wire grant_valid;
wire [CL_S_COUNT:0] grant_encoded;
wire read = grant_encoded[0];
assign s_select = grant_encoded >> 1;
arbiter #(
.PORTS(S_COUNT*2),
.TYPE("ROUND_ROBIN"),
.BLOCK("ACKNOWLEDGE"),
.LSB_PRIORITY("HIGH")
)
arb_inst (
.clk(clk),
.rst(rst),
.request(request),
.acknowledge(acknowledge),
.grant(grant),
.grant_valid(grant_valid),
.grant_encoded(grant_encoded)
);
genvar n;
// request generation
generate
for (n = 0; n < S_COUNT; n = n + 1) begin
assign request[2*n] = s_axil_awvalid[n];
assign request[2*n+1] = s_axil_arvalid[n];
end
endgenerate
// acknowledge generation
generate
for (n = 0; n < S_COUNT; n = n + 1) begin
assign acknowledge[2*n] = grant[2*n] && s_axil_bvalid[n] && s_axil_bready[n];
assign acknowledge[2*n+1] = grant[2*n+1] && s_axil_rvalid[n] && s_axil_rready[n];
end
endgenerate
always @* begin
state_next = STATE_IDLE;
match = 1'b0;
m_select_next = m_select_reg;
axil_addr_next = axil_addr_reg;
axil_addr_valid_next = axil_addr_valid_reg;
axil_prot_next = axil_prot_reg;
axil_data_next = axil_data_reg;
axil_wstrb_next = axil_wstrb_reg;
axil_resp_next = axil_resp_reg;
s_axil_awready_next = 0;
s_axil_wready_next = 0;
s_axil_bvalid_next = s_axil_bvalid_reg & ~s_axil_bready;
s_axil_arready_next = 0;
s_axil_rvalid_next = s_axil_rvalid_reg & ~s_axil_rready;
m_axil_awvalid_next = m_axil_awvalid_reg & ~m_axil_awready;
m_axil_wvalid_next = m_axil_wvalid_reg & ~m_axil_wready;
m_axil_bready_next = 0;
m_axil_arvalid_next = m_axil_arvalid_reg & ~m_axil_arready;
m_axil_rready_next = 0;
case (state_reg)
STATE_IDLE: begin
// idle state; wait for arbitration
if (grant_valid) begin
axil_addr_valid_next = 1'b1;
if (read) begin
// reading
axil_addr_next = current_s_axil_araddr;
axil_prot_next = current_s_axil_arprot;
s_axil_arready_next[s_select] = 1'b1;
end else begin
// writing
axil_addr_next = current_s_axil_awaddr;
axil_prot_next = current_s_axil_awprot;
s_axil_awready_next[s_select] = 1'b1;
end
state_next = STATE_DECODE;
end else begin
state_next = STATE_IDLE;
end
end
STATE_DECODE: begin
// decode state; determine master interface
match = 1'b0;
for (i = 0; i < M_COUNT; i = i + 1) begin
for (j = 0; j < M_REGIONS; j = j + 1) begin
if (M_ADDR_WIDTH[(i*M_REGIONS+j)*32 +: 32] && (!M_SECURE[i] || !axil_prot_reg[1]) && ((read ? M_CONNECT_READ : M_CONNECT_WRITE) & (1 << (s_select+i*S_COUNT))) && (axil_addr_reg >> M_ADDR_WIDTH[(i*M_REGIONS+j)*32 +: 32]) == (M_BASE_ADDR[(i*M_REGIONS+j)*ADDR_WIDTH +: ADDR_WIDTH] >> M_ADDR_WIDTH[(i*M_REGIONS+j)*32 +: 32])) begin
m_select_next = i;
match = 1'b1;
end
end
end
if (match) begin
if (read) begin
// reading
m_axil_rready_next[m_select_next] = 1'b1;
state_next = STATE_READ;
end else begin
// writing
s_axil_wready_next[s_select] = 1'b1;
state_next = STATE_WRITE;
end
end else begin
// no match; return decode error
axil_data_next = {DATA_WIDTH{1'b0}};
axil_resp_next = 2'b11;
if (read) begin
// reading
s_axil_rvalid_next[s_select] = 1'b1;
state_next = STATE_WAIT_IDLE;
end else begin
// writing
s_axil_wready_next[s_select] = 1'b1;
state_next = STATE_WRITE_DROP;
end
end
end
STATE_WRITE: begin
// write state; store and forward write data
s_axil_wready_next[s_select] = 1'b1;
if (axil_addr_valid_reg) begin
m_axil_awvalid_next[m_select_reg] = 1'b1;
end
axil_addr_valid_next = 1'b0;
if (current_s_axil_wready && current_s_axil_wvalid) begin
s_axil_wready_next[s_select] = 1'b0;
axil_data_next = current_s_axil_wdata;
axil_wstrb_next = current_s_axil_wstrb;
m_axil_wvalid_next[m_select_reg] = 1'b1;
m_axil_bready_next[m_select_reg] = 1'b1;
state_next = STATE_WRITE_RESP;
end else begin
state_next = STATE_WRITE;
end
end
STATE_WRITE_RESP: begin
// write response state; store and forward write response
m_axil_bready_next[m_select_reg] = 1'b1;
if (current_m_axil_bready && current_m_axil_bvalid) begin
m_axil_bready_next[m_select_reg] = 1'b0;
axil_resp_next = current_m_axil_bresp;
s_axil_bvalid_next[s_select] = 1'b1;
state_next = STATE_WAIT_IDLE;
end else begin
state_next = STATE_WRITE_RESP;
end
end
STATE_WRITE_DROP: begin
// write drop state; drop write data
s_axil_wready_next[s_select] = 1'b1;
axil_addr_valid_next = 1'b0;
if (current_s_axil_wready && current_s_axil_wvalid) begin
s_axil_wready_next[s_select] = 1'b0;
s_axil_bvalid_next[s_select] = 1'b1;
state_next = STATE_WAIT_IDLE;
end else begin
state_next = STATE_WRITE_DROP;
end
end
STATE_READ: begin
// read state; store and forward read response
m_axil_rready_next[m_select_reg] = 1'b1;
if (axil_addr_valid_reg) begin
m_axil_arvalid_next[m_select_reg] = 1'b1;
end
axil_addr_valid_next = 1'b0;
if (current_m_axil_rready && current_m_axil_rvalid) begin
m_axil_rready_next[m_select_reg] = 1'b0;
axil_data_next = current_m_axil_rdata;
axil_resp_next = current_m_axil_rresp;
s_axil_rvalid_next[s_select] = 1'b1;
state_next = STATE_WAIT_IDLE;
end else begin
state_next = STATE_READ;
end
end
STATE_WAIT_IDLE: begin
// wait for idle state; wait untl grant valid is deasserted
if (!grant_valid || acknowledge) begin
state_next = STATE_IDLE;
end else begin
state_next = STATE_WAIT_IDLE;
end
end
endcase
end
always @(posedge clk) begin
if (rst) begin
state_reg <= STATE_IDLE;
s_axil_awready_reg <= 0;
s_axil_wready_reg <= 0;
s_axil_bvalid_reg <= 0;
s_axil_arready_reg <= 0;
s_axil_rvalid_reg <= 0;
m_axil_awvalid_reg <= 0;
m_axil_wvalid_reg <= 0;
m_axil_bready_reg <= 0;
m_axil_arvalid_reg <= 0;
m_axil_rready_reg <= 0;
end else begin
state_reg <= state_next;
s_axil_awready_reg <= s_axil_awready_next;
s_axil_wready_reg <= s_axil_wready_next;
s_axil_bvalid_reg <= s_axil_bvalid_next;
s_axil_arready_reg <= s_axil_arready_next;
s_axil_rvalid_reg <= s_axil_rvalid_next;
m_axil_awvalid_reg <= m_axil_awvalid_next;
m_axil_wvalid_reg <= m_axil_wvalid_next;
m_axil_bready_reg <= m_axil_bready_next;
m_axil_arvalid_reg <= m_axil_arvalid_next;
m_axil_rready_reg <= m_axil_rready_next;
end
m_select_reg <= m_select_next;
axil_addr_reg <= axil_addr_next;
axil_addr_valid_reg <= axil_addr_valid_next;
axil_prot_reg <= axil_prot_next;
axil_data_reg <= axil_data_next;
axil_wstrb_reg <= axil_wstrb_next;
axil_resp_reg <= axil_resp_next;
end
endmodule