Separate constraint generation for element and its attribute - XSD

Good morning! I have the following element in an XML:
<estcivil unestavel="S">C</estcivil>

It turns out that my attribute can only receive "S" or "N" values, but the element has other value constraints, such as: "C", "S", "D", "V". How could I generate these two constraints in Schema XSD, one for the element and one for the attribute?.

My XSD looks like this:

<xs:element name="estcivil" maxOccurs="1" ref="ESTCIV">
 <xs:complexType>
  <xs:simpleContent>
   <xs:extension base="xs:string">
    <xs:attribute name="unestavel" use="required">
     <xs:simpleType>
      <xs:restriction base="xs:string">
        <xs:pattern value="S|N"/>
      </xs:restriction>
     </xs:simpleType>
    </xs:attribute>
   </xs:extension>
  </xs:simpleContent>
 </xs:complexType>
</xs:element>

being the ESTCIV:

<xs:simpleType name="ESTCIV">
    <xs:restriction base="xs:string">
        <xs:enumeration value="C"/>
        <xs:enumeration value="D"/>
        <xs:enumeration value="P"/>
        <xs:enumeration value="S"/>
        <xs:enumeration value="U"/>
        <xs:enumeration value="V"/>         
    </xs:restriction>
</xs:simpleType>

Thank you.