yosys/manual/PRESENTATION_ExOth/axis_master.v

28 lines
674 B
Verilog

module axis_master(aclk, aresetn, tvalid, tready, tdata);
input aclk, aresetn, tready;
output reg tvalid;
output reg [7:0] tdata;
reg [31:0] state;
always @(posedge aclk) begin
if (!aresetn) begin
state <= 314159265;
tvalid <= 0;
tdata <= 'bx;
end else begin
if (tvalid && tready)
tvalid <= 0;
if (!tvalid || !tready) begin
// ^- should be not inverted!
state = state ^ state << 13;
state = state ^ state >> 7;
state = state ^ state << 17;
if (state[9:8] == 0) begin
tvalid <= 1;
tdata <= state;
end
end
end
end
endmodule