private static function cbopcode13(Core $core)
{
$core->FCarry = ($core->registersHL & 0x1) == 0x1;
$core->registersHL = ($core->registersHL & 0xff00) + ($core->FCarry ? 0x80 : 0) + (($core->registersHL & 0xff) >> 1);
$core->FHalfCarry = $core->FSubtract = false;
$core->FZero = ($core->registersHL & 0xff) == 0x0;
}