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/*
* This is very similar to design/slave.v, although with 1 important difference
* - it's meant to be synthesizable (and use iCE40HX8K's embedded RAM).
*/
`default_nettype none
`define ADDR_WIDTH ($clog2(MEMORY_BLOCKS) + 8)
module embedded_bram_slave
#(
parameter MEMORY_BLOCKS = 1, /* 1 block stores 256 16-bit words */
parameter WORDS_TO_INITIALIZE = 0,
parameter INITIAL_CONTENTS_FILE = "some_file.mem"
)
(
output wire ACK_O,
input wire CLK_I,
input wire [`ADDR_WIDTH - 1:0] ADR_I,
input wire [15:0] DAT_I,
output wire [15:0] DAT_O,
input wire RST_I,
input wire STB_I,
input wire WE_I,
output wire STALL_O
);
reg [15:0] memory [256 * MEMORY_BLOCKS - 1 : 0];
generate
if (WORDS_TO_INITIALIZE) begin
initial
$readmemb(INITIAL_CONTENTS_FILE, memory, 0, WORDS_TO_INITIALIZE - 1);
end else begin
always @ (posedge CLK_I) begin
if (!RST_I && STB_I && WE_I)
memory[ADR_I] <= DAT_I;
end
end
endgenerate
reg [15:0] output_data;
reg ack;
assign DAT_O = output_data;
assign ACK_O = ack;
assign STALL_O = 0;
always @ (posedge CLK_I) begin
if (RST_I) begin
ack <= 0;
end else begin
ack <= STB_I;
output_data <= memory[ADR_I];
end
end
endmodule // embedded_bram_slave
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