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cvxif_fu.sv: add register to hold illegal instruction information (#939)

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It avoids that result from cvxif and illegal instruction use wb bus at the same time
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Guillaume Chauvon 2022-08-16 09:27:32 +02:00 • committed by GitHub
parent 80050aa21e
commit eb9881efbb
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1 changed files with 39 additions and 13 deletions
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52
core/cvxif_fu.sv
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@ -29,6 +29,10 @@ module cvxif_fu import ariane_pkg::*; (
input cvxif_pkg::cvxif_resp_t cvxif_resp_i
);
logic illegal_n, illegal_q;
logic [TRANS_ID_BITS-1:0] illegal_id_n, illegal_id_q;
logic [31:0] illegal_instr_n, illegal_instr_q;
always_comb begin
cvxif_req_o = '0;
cvxif_req_o.x_result_ready = 1'b1;
@ -50,22 +54,44 @@ module cvxif_fu import ariane_pkg::*; (
end
always_comb begin
if (~cvxif_resp_i.x_issue_resp.accept && cvxif_req_o.x_issue_valid && cvxif_resp_i.x_issue_ready) begin
x_trans_id_o = cvxif_req_o.x_issue_req.id;
x_result_o = 0;
x_valid_o = 1;
illegal_n = illegal_q;
illegal_id_n = illegal_id_q;
illegal_instr_n = illegal_instr_q;
if (~cvxif_resp_i.x_issue_resp.accept && cvxif_req_o.x_issue_valid && cvxif_resp_i.x_issue_ready && ~illegal_n) begin
illegal_n = 1'b1;
illegal_id_n = cvxif_req_o.x_issue_req.id;
illegal_instr_n = cvxif_req_o.x_issue_req.instr;
end
x_valid_o = cvxif_resp_i.x_result_valid; //Read result only when CVXIF is enabled
x_trans_id_o = x_valid_o ? cvxif_resp_i.x_result.id : '0;
x_result_o = x_valid_o ? cvxif_resp_i.x_result.data : '0;
x_exception_o.cause = x_valid_o ? cvxif_resp_i.x_result.exccode : '0;
x_exception_o.valid = x_valid_o ? cvxif_resp_i.x_result.exc : '0;
x_exception_o.tval = '0;
x_we_o = x_valid_o ? cvxif_resp_i.x_result.we : '0;
if (illegal_n) begin
if (~x_valid_o) begin
x_trans_id_o = illegal_id_n;
x_result_o = '0;
x_valid_o = 1'b1;
x_exception_o.cause = riscv::ILLEGAL_INSTR;
x_exception_o.valid = 1;
x_exception_o.tval = cvxif_req_o.x_issue_req.instr;
x_exception_o.valid = 1'b1;
x_exception_o.tval = illegal_instr_n;
x_we_o = '0;
illegal_n = '0; // Reset flag for illegal instr. illegal_id and illegal instr values are a don't care, no need to reset it.
end
end
end
always_ff @(posedge clk_i, negedge rst_ni) begin
if (~rst_ni) begin
illegal_q <= 1'b0;
illegal_id_q <= '0;
illegal_instr_q <= '0;
end else begin
x_valid_o = cvxif_resp_i.x_result_valid; //Read result only when CVXIF is enabled
x_trans_id_o = x_valid_o ? cvxif_resp_i.x_result.id : '0;
x_result_o = x_valid_o ? cvxif_resp_i.x_result.data : '0;
x_exception_o.cause = x_valid_o ? cvxif_resp_i.x_result.exccode : '0;
x_exception_o.valid = x_valid_o ? cvxif_resp_i.x_result.exc : '0;
x_exception_o.tval = '0;
x_we_o = x_valid_o ? cvxif_resp_i.x_result.we : '0;
illegal_q <= illegal_n;
illegal_id_q <= illegal_id_n;
illegal_instr_q <= illegal_instr_n;
end
end