$display – Print to screen a line followed by an automatic newline. $write – Print to screen a line without the newline. $swrite – Print to variable a line without the newline. $sscanf – Read from variable a format-specified string. (*Verilog-2001) $fopen – Open a handle to a file (read or write) $fdisplay – Print a line from a file followed by an automatic newline. $fwrite – Print to file a line without the newline. $fscanf – Read from file a format-specified string. (*Verilog-2001) $fclose – Close and release an open file handle. $readmemh – Read hex file content into a memory array. $readmemb – Read binary file content into a memory array. $monitor – Print out all the listed variables when any change value. $time – Value of current simulation time. $dumpfile – Declare the VCD (Value Change Dump) format output file name. $dumpvars – Turn on and dump the variables. $dumpports – Turn on and dump the variables in Extended-VCD format. $random – Return a random value.