Magento : Get all options of a dropdown or multiselect attribute
$arg_attribute = "manufacturer";//this may be any attribute code
//Object of attribute model
$attribute_model = Mage::getModel('eav/entity_attribute');
//Object of attribute options model
$attribute_options_model= Mage::getModel('eav/entity_attribute_source_table') ;
//
$attribute_code = $attribute_model->getIdByCode('catalog_product', $arg_attribute);
$attribute = $attribute_model->load($attribute_code);
$attribute_table =$attribute_options_model->setAttribute($attribute);
//Getting all options
$options = $attribute_options_model->getAllOptions(false);
//Printing all options of particular attribute
echo "<pre />";
print_r($options);
$arg_attribute = "manufacturer";//this may be any attribute code
//Object of attribute model
$attribute_model = Mage::getModel('eav/entity_attribute');
//Object of attribute options model
$attribute_options_model= Mage::getModel('eav/entity_attribute_source_table') ;
//
$attribute_code = $attribute_model->getIdByCode('catalog_product', $arg_attribute);
$attribute = $attribute_model->load($attribute_code);
$attribute_table =$attribute_options_model->setAttribute($attribute);
//Getting all options
$options = $attribute_options_model->getAllOptions(false);
//Printing all options of particular attribute
echo "<pre />";
print_r($options);