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`include "gfx/gfx_defs.sv"
module gfx_assembly
(
input logic clk,
rst_n,
input lane_word send_data,
input lane_mask send_mask,
input logic send_valid,
output logic send_ready,
input logic out_ready,
output logic out_valid,
output fp_xyzw out_vertex_a,
out_vertex_b,
out_vertex_c
);
localparam SETS_PER_TRI = 6;
mat4 sets[SETS_PER_TRI];
logic assemble_next, permit_out;
lane_mask current_mask, next_mask;
logic[1:0] out_lane;
logic[2:0] set_num;
enum int unsigned
{
GET_LANES,
ASSEMBLE
} state;
assign out_valid = permit_out && current_mask[out_lane];
assign out_vertex_a = sets[0][out_lane];
assign out_vertex_b = sets[2][out_lane];
assign out_vertex_c = sets[4][out_lane];
assign next_mask = current_mask & send_mask;
assign assemble_next = !current_mask[out_lane] || out_ready;
always_ff @(posedge clk or negedge rst_n)
if (!rst_n) begin
state <= GET_LANES;
set_num <= 0;
out_lane <= 0;
permit_out <= 0;
send_ready <= 1;
current_mask <= {($bits(current_mask)){1'b1}};
end else unique case (state)
GET_LANES:
if (send_valid) begin
set_num <= set_num + 1;
current_mask <= next_mask;
if (set_num == SETS_PER_TRI - 1) begin
state <= ASSEMBLE;
permit_out <= 1;
send_ready <= 0;
end
if (!(|next_mask)) begin
state <= GET_LANES;
set_num <= 0;
current_mask <= {($bits(current_mask)){1'b1}};
end
end
ASSEMBLE:
if (assemble_next) begin
out_lane <= out_lane + 1;
if (&out_lane) begin
state <= GET_LANES;
permit_out <= 0;
send_ready <= 1;
end
end
endcase
always_ff @(posedge clk)
unique case (state)
GET_LANES:
if (send_valid)
sets[set_num] <= send_data;
ASSEMBLE: ;
endcase
endmodule
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