$ivlh_attribute_event	vpiSysFuncSized 1 unsigned
$ivlh_rising_edge	vpiSysFuncSized 1 unsigned
$ivlh_falling_edge	vpiSysFuncSized 1 unsigned

$ivlh_shift_left        vpiSysFuncSized 32 unsigned
$ivlh_shift_right       vpiSysFuncSized 32 unsigned