单双口RAM

// Quartus II Verilog Template
// Simple Dual Port RAM with separate read/write addresses and
// single read/write clock

module simple_dual_port_ram_single_clock
#(parameter DATA_WIDTH=8, parameter ADDR_WIDTH=6)
(
input [(DATA_WIDTH-1):0] data,
input [(ADDR_WIDTH-1):0] read_addr, write_addr,
input we, clk,
output reg [(DATA_WIDTH-1):0] q
);

// Declare the RAM variable
reg [DATA_WIDTH-1:0] ram[2**ADDR_WIDTH-1:0];

always @ (posedge clk)
begin
// Write
if (we)
ram[write_addr] <= data;

// Read (if read_addr == write_addr, return OLD data). To return
// NEW data, use = (blocking write) rather than <= (non-blocking write)
// in the write assignment. NOTE: NEW data may require extra bypass
// logic around the RAM.
q <= ram[read_addr];
end

endmodule

// Quartus II Verilog Template
// True Dual Port RAM with dual clocks

module true_dual_port_ram_dual_clock
#(parameter DATA_WIDTH=8, parameter ADDR_WIDTH=6)
(
input [(DATA_WIDTH-1):0] data_a, data_b,
input [(ADDR_WIDTH-1):0] addr_a, addr_b,
input we_a, we_b, clk_a, clk_b,
output reg [(DATA_WIDTH-1):0] q_a, q_b
);

// Declare the RAM variable
reg [DATA_WIDTH-1:0] ram[2**ADDR_WIDTH-1:0];

always @ (posedge clk_a)
begin
// Port A
if (we_a)
begin
ram[addr_a] <= data_a;
q_a <= data_a;
end
else
begin
q_a <= ram[addr_a];
end
end

always @ (posedge clk_b)
begin
// Port B
if (we_b)
begin
ram[addr_b] <= data_b;
q_b <= data_b;
end
else
begin
q_b <= ram[addr_b];
end
end

endmodule

引自：Quartus II 13.1 insert template