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88 lines
No EOL
2.7 KiB
Systemverilog
88 lines
No EOL
2.7 KiB
Systemverilog
`include "VX_platform.vh"
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`TRACING_OFF
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module VX_matrix_arbiter #(
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parameter NUM_REQS = 1,
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parameter LOCK_ENABLE = 0,
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parameter LOG_NUM_REQS = $clog2(NUM_REQS)
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) (
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input wire clk,
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input wire reset,
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input wire enable,
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input wire [NUM_REQS-1:0] requests,
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output wire [LOG_NUM_REQS-1:0] grant_index,
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output wire [NUM_REQS-1:0] grant_onehot,
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output wire grant_valid
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);
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if (NUM_REQS == 1) begin
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`UNUSED_VAR (clk)
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`UNUSED_VAR (reset)
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assign grant_index = 0;
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assign grant_onehot = requests;
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assign grant_valid = requests[0];
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end else begin
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reg [NUM_REQS-1:1] state [NUM_REQS-1:0];
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wire [NUM_REQS-1:0] pri [NUM_REQS-1:0];
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wire [NUM_REQS-1:0] grant_unqual;
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for (genvar i = 0; i < NUM_REQS; i++) begin
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for (genvar j = 0; j < NUM_REQS; j++) begin
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if (j > i) begin
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assign pri[j][i] = requests[i] && state[i][j];
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end
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else if (j < i) begin
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assign pri[j][i] = requests[i] && !state[j][i];
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end
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else begin
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assign pri[j][i] = 0;
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end
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end
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assign grant_unqual[i] = requests[i] && !(| pri[i]);
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end
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for (genvar i = 0; i < NUM_REQS; i++) begin
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for (genvar j = i + 1; j < NUM_REQS; j++) begin
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always @(posedge clk) begin
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if (reset) begin
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state[i][j] <= 0;
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end else begin
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state[i][j] <= (state[i][j] || grant_unqual[j]) && !grant_unqual[i];
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end
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end
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end
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end
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if (LOCK_ENABLE == 0) begin
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`UNUSED_VAR (enable)
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assign grant_onehot = grant_unqual;
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end else begin
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reg [NUM_REQS-1:0] grant_unqual_prev;
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always @(posedge clk) begin
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if (reset) begin
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grant_unqual_prev <= 0;
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end else if (enable) begin
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grant_unqual_prev <= grant_unqual;
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end
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end
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assign grant_onehot = enable ? grant_unqual : grant_unqual_prev;
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end
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VX_onehot_encoder #(
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.N (NUM_REQS)
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) encoder (
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.data_in (grant_unqual),
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.data_out (grant_index),
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`UNUSED_PIN (valid_out)
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);
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assign grant_valid = (| requests);
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end
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endmodule
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`TRACING_ON |