#!/usr/bin/perl

use Getopt::Long;

use integer;

$helpusage = "placeholder";

GetOptions ('total_int=s'       => \$total_int)|| die("$helpusage");

$LEN=15;

#printf("logic [2:0] mask;\n");

printf("// mask[3:0] = { 4'b1000 - 30b mask,4'b0100 - 31b mask, 4'b0010 - 28b mask, 4'b0001 - 32b mask }\n");
printf("always_comb begin\n");
printf("  case \(address[14:0]\)\n");
printf("    15'b011000000000000 : mask[3:0] = 4'b0100;\n");
for ($i=1; $i<=$total_int; $i++) {
    $j=hex("4000");
    printf("    15'b%s : mask[3:0] = 4'b1000;\n",d2b($j+$i*4));
}
for ($i=1; $i<=$total_int; $i++) {
    $j=hex("2000");
    printf("    15'b%s : mask[3:0] = 4'b0100;\n",d2b($j+$i*4));
}
for ($i=1; $i<=$total_int; $i++) {
    $j=hex("0");
    printf("    15'b%s : mask[3:0] = 4'b0010;\n",d2b($j+$i*4));
}
    printf("    %-17s : mask[3:0] = 4'b0001;\n","default");
printf("  endcase\n");
printf("end\n");


sub b2d {
    my ($v) = @_;

    $v = oct("0b" . $v);

    return($v);
}

sub d2b {
    my ($v) = @_;

    my $repeat;

    $v = sprintf "%b",$v;
    if (length($v)<$LEN) {
        $repeat=$LEN-length($v);
        $v="0"x$repeat.$v;
    }
    elsif (length($v)>$LEN) {
        $v=substr($v,length($v)-$LEN,$LEN);
    }

    return($v);
}