pram.v

这是著名的硬件调试工具debussy的教学说明

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/* Debussy tutorial case: A simplified microprogramming-based CPU
   file name: pram.v
   description: This part modelize the program memory for the system operation

		clock: system clock
		VMA: valid memory address where read/write can be performed
		R_W: memory read or memory write
		addr: 8-bits address bus
		data: 8-bits data bus
*/

module pram(clock,VMA,R_W,addr,data);
input clock;
input VMA;
input R_W;
input [7:0] addr;
inout [7:0] data;

reg [7:0] macroram [255:0];
reg [7:0] dataout;

assign data = R_W ? dataout : 8'hz;

always @(posedge (clock & VMA))
begin
  	$fsdbDumpMem(macroram, 0, 256);
	if (R_W == 1) dataout=macroram[addr];
	else macroram[addr]=data;
end
initial
   begin
        $readmemb("../memory/pram.dat",macroram);
    end
endmodule