tinyriscv/rtl/sys_bus/obi_interconnect.sv

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/*
Copyright 2021 Blue Liang, liangkangnan@163.com
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
// obi总线交叉互联矩阵支持一对多、多对一、多对多
// master之间采用优先级总裁方式LSB优先级最高MSB优先级最低
module obi_interconnect #(
parameter int MASTERS = 3, // number of masters
parameter int SLAVES = 5, // number of slaves
parameter MASTER_BITS = MASTERS == 1 ? 1 : $clog2(MASTERS), // do not change
parameter SLAVE_BITS = SLAVES == 1 ? 1 : $clog2(SLAVES) // do not change
)(
input logic clk_i,
input logic rst_ni,
input logic master_req_i [MASTERS],
output logic master_gnt_o [MASTERS],
output logic master_rvalid_o [MASTERS],
input logic master_we_i [MASTERS],
input logic [ 3:0] master_be_i [MASTERS],
input logic [31:0] master_addr_i [MASTERS],
input logic [31:0] master_wdata_i [MASTERS],
output logic [31:0] master_rdata_o [MASTERS],
input logic [31:0] slave_addr_mask_i [SLAVES],
input logic [31:0] slave_addr_base_i [SLAVES],
output logic slave_req_o [SLAVES],
input logic slave_gnt_i [SLAVES],
input logic slave_rvalid_i [SLAVES],
output logic slave_we_o [SLAVES],
output logic [ 3:0] slave_be_o [SLAVES],
output logic [31:0] slave_addr_o [SLAVES],
output logic [31:0] slave_wdata_o [SLAVES],
input logic [31:0] slave_rdata_i [SLAVES]
);
genvar m, s;
logic [MASTER_BITS-1:0] master_sel_int[SLAVES];
logic [MASTERS-1:0] master_sel_vec[SLAVES];
logic granted_master[SLAVES];
// 为每个slave选择一个master
generate
for (s = 0; s < SLAVES; s = s + 1) begin: master_sel
obi_interconnect_master_sel #(
.MASTERS(MASTERS)
) master_sel (
.clk_i(clk_i),
.rst_ni(rst_ni),
.master_req_i(master_req_i),
.master_addr_i(master_addr_i),
.slave_addr_mask_i(slave_addr_mask_i[s]),
.slave_addr_base_i(slave_addr_base_i[s]),
.master_sel_int_o(master_sel_int[s]),
.master_sel_vec_o(master_sel_vec[s]),
.granted_master_o(granted_master[s])
);
end
endgenerate
logic [SLAVE_BITS-1:0] slave_sel_int[MASTERS];
// 为每个master选择一个slave
generate
for (m = 0; m < MASTERS; m = m + 1) begin: slave_sel
obi_interconnect_slave_sel #(
.SLAVES(SLAVES)
) slave_sel (
.clk_i(clk_i),
.rst_ni(rst_ni),
.master_req_i(master_req_i[m]),
.master_addr_i(master_addr_i[m]),
.slave_addr_mask_i(slave_addr_mask_i),
.slave_addr_base_i(slave_addr_base_i),
.slave_sel_int_o(slave_sel_int[m])
);
end
endgenerate
// slave信号赋值
generate
for (s = 0; s < SLAVES; s = s + 1) begin: slave_signals
assign slave_req_o[s] = master_req_i[master_sel_int[s]] & granted_master[s];
assign slave_we_o[s] = master_we_i[master_sel_int[s]] & granted_master[s];
assign slave_be_o[s] = master_be_i[master_sel_int[s]];
assign slave_addr_o[s] = master_addr_i[master_sel_int[s]];
assign slave_wdata_o[s] = master_wdata_i[master_sel_int[s]];
end
endgenerate
// 真正被slaves选中的master
logic [MASTERS-1:0] master_sel_or;
always_comb begin
master_sel_or = 'b0;
for (integer i = 0; i < SLAVES; i = i + 1) begin: gen_master_sel_or_vec
master_sel_or = master_sel_or | (master_sel_vec[i] & {MASTERS{granted_master[i]}});
end
end
// 保存master选中的slave
logic [SLAVE_BITS-1:0] slave_sel_int_q[MASTERS];
generate
for (m = 0; m < MASTERS; m = m + 1) begin: gen_save_selected_slaves
always_ff @ (posedge clk_i or negedge rst_ni) begin
if (!rst_ni) begin
slave_sel_int_q[m] <= 'b0;
end else begin
if (slave_gnt_i[slave_sel_int[m]] & master_sel_or[m]) begin
slave_sel_int_q[m] <= slave_sel_int[m];
end
end
end
end
endgenerate
// master信号赋值
generate
for (m = 0; m < MASTERS; m = m + 1) begin: master_signals
assign master_gnt_o[m] = slave_gnt_i[slave_sel_int[m]] & master_sel_or[m];
assign master_rdata_o[m] = slave_rdata_i[slave_sel_int_q[m]];
assign master_rvalid_o[m] = slave_rvalid_i[slave_sel_int_q[m]];
end
endgenerate
endmodule