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|
module bus_master
(
input logic clk,
rst,
input logic[29:0] addr,
input logic start,
write,
output logic ready,
output logic[31:0] data_rd,
input logic[31:0] data_wr,
output logic[31:0] avl_address,
output logic avl_read,
avl_write,
input logic[31:0] avl_readdata,
output logic[31:0] avl_writedata,
input logic avl_waitrequest,
output logic[3:0] avl_byteenable
);
enum {
REQUEST,
WAIT,
RESPONSE
} state;
assign data_rd = avl_readdata;
assign avl_byteenable = 4'b1111;
always_ff @(posedge clk) unique case(state)
REQUEST: if(start) begin
avl_address <= {addr, 2'b00};
avl_read <= ~write;
avl_write <= write;
avl_writedata <= data_wr;
state <= WAIT;
end
WAIT: if(~avl_waitrequest) begin
ready <= 1;
state <= RESPONSE;
end
RESPONSE: begin
ready <= 0;
avl_read <= 0;
avl_write <= 0;
state <= REQUEST;
end
endcase
initial begin
ready = 0;
avl_read = 0;
avl_write = 0;
state = REQUEST;
end
endmodule
|
