board.xsd

<?xml version="1.0"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema"
    elementFormDefault="qualified">
    
    
    <xs:group name="components">
        <xs:sequence>
            <xs:choice minOccurs="0" maxOccurs="unbounded">
                <xs:element name="led" type="led"/>
                <xs:element name="button" type="button"/>
                <xs:element name="lcd" type="lcd"/>
                <xs:element name="sram" type="sram"/>
            </xs:choice>
        </xs:sequence>
    </xs:group>
    
    <xs:element name="board">
        <xs:complexType>
            <xs:sequence>
                <xs:group ref="components"/>
                <xs:element name="gui" type="layout" minOccurs="0"/>
                <xs:group ref="components"/>
            </xs:sequence>
        </xs:complexType>
    </xs:element>
    
    
    <xs:complexType name="component">
        <xs:attribute name="id" type="xs:ID"/>
    </xs:complexType>
    
    <xs:complexType name="led">
        <xs:complexContent>
            <xs:extension base="component">
                <xs:all>
                    <xs:element name="in" type="irq"/>
                </xs:all>
                <xs:attribute name="highOn" type="xs:boolean" default="false"/>
            </xs:extension>
        </xs:complexContent>
    </xs:complexType>
    
    <xs:complexType name="button">
        <xs:complexContent>
            <xs:extension base="component">
                <xs:all>
                    <xs:element name="out" type="irq"/>
                    <xs:element name="key" type="glfwKey" minOccurs="0"/>
                </xs:all>
            </xs:extension>
        </xs:complexContent>
    </xs:complexType>
    
    <xs:complexType name="lcd">
        <xs:complexContent>
            <xs:extension base="component">
                <xs:all>
                    <xs:element name="d4" type="irq"/>
                    <xs:element name="d5" type="irq"/>
                    <xs:element name="d6" type="irq"/>
                    <xs:element name="d7" type="irq"/>
                    <xs:element name="rs" type="irq"/>
                    <xs:element name="en" type="irq"/>
                    <xs:element name="rw" type="irq"/>
                    <xs:element name="optional" type="lcdIRQsSecondNibble" minOccurs="0"/>
                </xs:all>
                <xs:attribute name="width" type="xs:integer" use="required"/>
                <xs:attribute name="height" type="xs:integer" use="required"/>
            </xs:extension>
        </xs:complexContent>