In reply to dave_59:
Yes, mem_trace.txt is a file in the same directory,
code in PDP11_pkg.sv
function logic [`INSTR_WORD-1:0] get_Mem_Value( input logic [`INSTR_WORD-1:0]Address, input logic [`WORD-1:0] bytemode,input logic [`WORD-1:0] mem_op);
integer file, fp;
fp = $fopen("mem_trace.txt","a");
$display("fp: %d",fp);
if(mem_op === FETCH)
$fwrite(fp,"%3d\t\t%6o\n",FETCH,Address);
else if(mem_op === READ)
$fwrite(fp,"%3d\t\t%6o\n",READ,Address);
$fclose(fp);
endfunction
code in PDP11_ISA.sv
`include PDP11_pkg.sv
module PDP11_ISA();
logic [`INSTR_WORD-1:0] start_addr, opcode, temp_PC, temp_eff_addr, src_data, dst_data, dst_data_temp;
instr_fetch_decode(strt_addr.atooct());
while(1)begin
dst_data = get_Mem_Value(temp_eff_addr,bytemode,READ);
end
task instr_fetch_decode (input logic [`INSTR_WORD-1:0] start_addr);
integer fp;
PC = start_addr;
fp = $fopen("mem_trace.txt","w");
$display("fp: %d",fp); //logging a memory trace file
$fclose(fp);
endtask
endmodule