fifomem2.v

使用VHDL编程的异步FIFO程序 经调试可运行

module fifomem2 (rdata, wdata, waddr, raddr, wclken, wclk); 
parameter DATASIZE = 8; // Memory data word width 
parameter ADDRSIZE = 4; // Number of memory address bits 
parameter DEPTH = 1<<ADDRSIZE; // DEPTH = 2**ADDRSIZE 
output [DATASIZE-1:0] rdata; 
input [DATASIZE-1:0] wdata; 
input [ADDRSIZE-1:0] waddr, raddr; 
input wclken, wclk; 
`ifdef VENDORRAM 
// instantiation of a vendor's dual-port RAM 
VENDOR_RAM MEM (.dout(rdata), .din(wdata), 
.waddr(waddr), .raddr(raddr), 
.wclken(wclken), .clk(wclk)); 
`else 
reg [DATASIZE-1:0] MEM [0:DEPTH-1]; 
assign rdata = MEM[raddr]; 
always @(posedge wclk) 
if (wclken) MEM[waddr] <= wdata; 
`endif 
endmodule