<?xml version='1.0' encoding='utf-8'?>
<!DOCTYPE register_page SYSTEM "registers.dtd">
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<register_page>
  <registers>
  
    <register execution_state="AArch32" is_register="True" is_internal="True" is_stub_entry="False">
      <reg_short_name>ICC_IGRPEN1</reg_short_name>
        
        <reg_long_name>Interrupt Controller Interrupt Group 1 Enable register</reg_long_name>



      
            <reg_condition otherwise="UNDEFINED">when FEAT_AA32EL1 is implemented and GICv3 is implemented</reg_condition>
      




          <reg_reset_value></reg_reset_value>

      <reg_mappings>
        



    
      
      <reg_mapping>
        
  

    

  

    <mapped_name filename="AArch64-icc_igrpen1_el1.xml">ICC_IGRPEN1_EL1</mapped_name>
  <mapped_type>Architectural</mapped_type>
      <mapped_execution_state>AArch64</mapped_execution_state>
    <mapped_from_startbit>31</mapped_from_startbit>
    <mapped_from_endbit>0</mapped_from_endbit>
    <mapped_from_sec_state>ICC_IGRPEN1_S</mapped_from_sec_state>
    <mapped_to_startbit>31</mapped_to_startbit>
    <mapped_to_endbit>0</mapped_to_endbit>
        <mapped_to_sec_state>ICC_IGRPEN1_EL1_S</mapped_to_sec_state>
    <mapped_from_rangeset output="31:0">
      <range>
        <msb>31</msb>
        <lsb>0</lsb>
      </range>
    </mapped_from_rangeset>
    <mapped_to_rangeset output="31:0">
      <range>
        <msb>31</msb>
        <lsb>0</lsb>
      </range>
    </mapped_to_rangeset>

      </reg_mapping>
    
      
      <reg_mapping>
        
  

    

  

    <mapped_name filename="AArch64-icc_igrpen1_el1.xml">ICC_IGRPEN1_EL1</mapped_name>
  <mapped_type>Architectural</mapped_type>
      <mapped_execution_state>AArch64</mapped_execution_state>
    <mapped_from_startbit>31</mapped_from_startbit>
    <mapped_from_endbit>0</mapped_from_endbit>
    <mapped_from_sec_state>ICC_IGRPEN1_NS</mapped_from_sec_state>
    <mapped_to_startbit>31</mapped_to_startbit>
    <mapped_to_endbit>0</mapped_to_endbit>
        <mapped_to_sec_state>ICC_IGRPEN1_EL1_NS</mapped_to_sec_state>
    <mapped_from_rangeset output="31:0">
      <range>
        <msb>31</msb>
        <lsb>0</lsb>
      </range>
    </mapped_from_rangeset>
    <mapped_to_rangeset output="31:0">
      <range>
        <msb>31</msb>
        <lsb>0</lsb>
      </range>
    </mapped_to_rangeset>

      </reg_mapping>

      </reg_mappings>

        <reg_purpose>
          
    
      <purpose_text>
        <para>Controls whether Group 1 interrupts are enabled for the current Security state.</para>
      </purpose_text>

        </reg_purpose>

      <reg_groups>
            <reg_group>GIC control registers</reg_group>
            <reg_group>GIC</reg_group>
      </reg_groups>
      
      
        
        <reg_banking>
            <reg_bank>
                <bank_text>This register is banked between ICC_IGRPEN1 and ICC_IGRPEN1_S and ICC_IGRPEN1_NS.</bank_text>
            </reg_bank>
        </reg_banking>
      <reg_attributes>
          
    
      <attributes_text>
        <para>ICC_IGRPEN1 is a 32-bit register.</para>

      </attributes_text>
      <attributes_text>
        <para>This register has the following instances:</para>

      </attributes_text>
      <attributes_text>
        <list type="unordered">
<listitem><content>ICC_IGRPEN1, when EL3 is not implemented or FEAT_AA64 is implemented.</content>
</listitem><listitem><content>ICC_IGRPEN1_S, when FEAT_AA32EL3 is implemented.</content>
</listitem><listitem><content>ICC_IGRPEN1_NS, when FEAT_AA32EL3 is implemented.</content>
</listitem></list>
      </attributes_text>

      </reg_attributes>
      <reg_fieldsets>
        






<fields id="fieldset_0" length="32">
  <text_before_fields/>
  <field id="fieldset_0-31_1" has_partial_fieldset="False" is_linked_to_partial_fieldset="False" is_access_restriction_possible="False" is_variable_length="False" is_constant_value="False" is_partial_field="False" is_conditional_field_name="False" rwtype="RES0">
    <field_msb>31</field_msb>
    <field_lsb>1</field_lsb>
    <rel_range>31:1</rel_range>
    <field_description order="before"/>
    <field_description order="before">
      <para>Reserved, <arm-defined-word>RES0</arm-defined-word>.</para>
    </field_description>
  </field>
  <field id="fieldset_0-0_0" has_partial_fieldset="False" is_linked_to_partial_fieldset="False" is_access_restriction_possible="False" is_variable_length="False" is_constant_value="False" is_partial_field="False" is_conditional_field_name="False">
    <field_name>Enable</field_name>
    <field_msb>0</field_msb>
    <field_lsb>0</field_lsb>
    <rel_range>0</rel_range>
    <field_description order="before">
      <para>Enables Group 1 interrupts for the current Security state.</para>
    </field_description>
    <field_description order="after"><para>Virtual accesses to this register update <register_link state="AArch32" id="AArch32-ich_vmcr.xml">ICH_VMCR</register_link>.VENG1.</para>
<para>If EL3 is present:</para>
<list type="unordered">
<listitem><content>This bit is a read/write alias of <register_link state="AArch32" id="AArch32-icc_mgrpen1.xml">ICC_MGRPEN1</register_link>.EnableGrp1{S, NS} as appropriate if EL3 is using AArch32, or <register_link state="AArch64" id="AArch64-icc_igrpen1_el3.xml">ICC_IGRPEN1_EL3</register_link>.EnableGrp1{S, NS} as appropriate if EL3 is using AArch64.</content>
</listitem><listitem><content>When this register is accessed at EL3, the copy of this register appropriate to the current setting of <register_link state="AArch32" id="AArch32-scr.xml">SCR</register_link>.NS is accessed.</content>
</listitem></list></field_description>
    <field_values impdef="False">
      <field_value_instance>
        <field_value>0b0</field_value>
        <field_value_description>
          <para>Group 1 interrupts are disabled for the current Security state.</para>
        </field_value_description>
      </field_value_instance>
      <field_value_instance>
        <field_value>0b1</field_value>
        <field_value_description>
          <para>Group 1 interrupts are enabled for the current Security state.</para>
        </field_value_description>
      </field_value_instance>
    </field_values>
    <field_resets>
      <field_reset reset_type="Warm">
        <field_reset_number>'0'</field_reset_number>
      </field_reset>
    </field_resets>
  </field>
  <text_after_fields/>
</fields>




<reg_fieldset length="32">
  <fieldat id="fieldset_0-31_1" msb="31" lsb="1"/>
  <fieldat id="fieldset_0-0_0" msb="0" lsb="0"/>
</reg_fieldset>


      </reg_fieldsets>

      <access_mechanisms>
          


  
    
      <access_permission_text>
        <para>The lowest Exception level at which this register can be accessed is governed by the Exception level to which IRQ is routed. This routing depends on the IRQ and NS fields of <register_link state="AArch32" id="AArch32-scr.xml">SCR</register_link> or <register_link state="AArch64" id="AArch64-scr_el3.xml">SCR_EL3</register_link> and the IMO field of <register_link state="AArch32" id="AArch32-hcr.xml">HCR</register_link> or <register_link state="AArch64" id="AArch64-hcr_el2.xml">HCR_EL2</register_link>.</para>

      </access_permission_text>
      <access_permission_text>
        <para>If an interrupt is pending within the CPU interface when Enable becomes 0, the interrupt must be released to allow the Distributor to forward the interrupt to a different PE.</para>
      </access_permission_text>





    
        
        <access_mechanism accessor="MRC ICC_IGRPEN1" type="SystemAccessor">
            <encoding>
            <access_instruction>MRC{&lt;c&gt;}{&lt;q&gt;} &lt;coproc&gt;, {#}&lt;opc1&gt;, &lt;Rt&gt;, &lt;CRn&gt;, &lt;CRm&gt;{, {#}&lt;opc2&gt;}</access_instruction>
                
                <enc n="coproc" v="0b1111"/>
                
                <enc n="opc1" v="0b000"/>
                
                <enc n="CRn" v="0b1100"/>
                
                <enc n="CRm" v="0b1100"/>
                
                <enc n="opc2" v="0b111"/>
            </encoding>
            <access_permission>
                <ps name="MRC" sections="1" secttype="access_permission">
                <pstext>
if !(IsFeatureImplemented(FEAT_AA32EL1) &amp;&amp; IsFeatureImplemented(FEAT_GICv3)) then
    Undefined();
elsif PSTATE.EL == EL0 then
    Undefined();
elsif PSTATE.EL == EL1 then
    if HaveEL(EL3) &amp;&amp; EL3SDDUndefPriority() &amp;&amp; IsFeatureImplemented(FEAT_AA64EL3) &amp;&amp; !ELUsingAArch32(EL3) &amp;&amp; SCR_EL3().IRQ == '1' then
        Undefined();
    elsif HaveEL(EL3) &amp;&amp; EL3SDDUndefPriority() &amp;&amp; IsFeatureImplemented(FEAT_AA32EL3) &amp;&amp; ELUsingAArch32(EL3) &amp;&amp; PSTATE.M != M32_Monitor &amp;&amp; SCR().IRQ == '1' then
        Undefined();
    elsif EL2Enabled() &amp;&amp; IsFeatureImplemented(FEAT_AA64EL2) &amp;&amp; !ELUsingAArch32(EL2) &amp;&amp; HSTR_EL2().T12 == '1' then
        AArch64_AArch32SystemAccessTrap(EL2, 0x03);
    elsif EL2Enabled() &amp;&amp; IsFeatureImplemented(FEAT_AA32EL2) &amp;&amp; ELUsingAArch32(EL2) &amp;&amp; HSTR().T12 == '1' then
        AArch32_TakeHypTrapException(0x03);
    elsif ICC_SRE().SRE == '0' then
        Undefined();
    elsif EL2Enabled() &amp;&amp; IsFeatureImplemented(FEAT_AA64EL2) &amp;&amp; !ELUsingAArch32(EL2) &amp;&amp; ICH_HCR_EL2().TALL1 == '1' then
        AArch64_AArch32SystemAccessTrap(EL2, 0x03);
    elsif EL2Enabled() &amp;&amp; IsFeatureImplemented(FEAT_AA32EL2) &amp;&amp; ELUsingAArch32(EL2) &amp;&amp; ICH_HCR().TALL1 == '1' then
        AArch32_TakeHypTrapException(0x03);
    elsif EL2Enabled() &amp;&amp; IsFeatureImplemented(FEAT_AA64EL2) &amp;&amp; !ELUsingAArch32(EL2) &amp;&amp; HCR_EL2().IMO == '1' then
        R(t) = ICV_IGRPEN1();
    elsif EL2Enabled() &amp;&amp; IsFeatureImplemented(FEAT_AA32EL2) &amp;&amp; ELUsingAArch32(EL2) &amp;&amp; HCR().IMO == '1' then
        R(t) = ICV_IGRPEN1();
    elsif HaveEL(EL3) &amp;&amp; IsFeatureImplemented(FEAT_AA64EL3) &amp;&amp; !ELUsingAArch32(EL3) &amp;&amp; SCR_EL3().IRQ == '1' then
        if EL3SDDUndef() then
            Undefined();
        else
            AArch64_AArch32SystemAccessTrap(EL3, 0x03);
        end;
    elsif HaveEL(EL3) &amp;&amp; IsFeatureImplemented(FEAT_AA32EL3) &amp;&amp; ELUsingAArch32(EL3) &amp;&amp; PSTATE.M != M32_Monitor &amp;&amp; SCR().IRQ == '1' then
        if EL3SDDUndef() then
            Undefined();
        else
            AArch32_TakeMonitorTrapException();
        end;
    elsif HaveEL(EL3) then
        R(t) = ICC_IGRPEN1_NS();
    else
        R(t) = ICC_IGRPEN1();
    end;
elsif PSTATE.EL == EL2 then
    if HaveEL(EL3) &amp;&amp; EL3SDDUndefPriority() &amp;&amp; IsFeatureImplemented(FEAT_AA64EL3) &amp;&amp; !ELUsingAArch32(EL3) &amp;&amp; SCR_EL3().IRQ == '1' then
        Undefined();
    elsif HaveEL(EL3) &amp;&amp; EL3SDDUndefPriority() &amp;&amp; IsFeatureImplemented(FEAT_AA32EL3) &amp;&amp; ELUsingAArch32(EL3) &amp;&amp; SCR().IRQ == '1' then
        Undefined();
    elsif ICC_HSRE().SRE == '0' then
        Undefined();
    elsif HaveEL(EL3) &amp;&amp; IsFeatureImplemented(FEAT_AA64EL3) &amp;&amp; !ELUsingAArch32(EL3) &amp;&amp; SCR_EL3().IRQ == '1' then
        if EL3SDDUndef() then
            Undefined();
        else
            AArch64_AArch32SystemAccessTrap(EL3, 0x03);
        end;
    elsif HaveEL(EL3) &amp;&amp; IsFeatureImplemented(FEAT_AA32EL3) &amp;&amp; ELUsingAArch32(EL3) &amp;&amp; SCR().IRQ == '1' then
        if EL3SDDUndef() then
            Undefined();
        else
            AArch32_TakeMonitorTrapException();
        end;
    elsif HaveEL(EL3) then
        R(t) = ICC_IGRPEN1_NS();
    else
        R(t) = ICC_IGRPEN1();
    end;
elsif PSTATE.EL == EL3 then
    if ICC_MSRE().SRE == '0' then
        Undefined();
    else
        if EffectiveSCR_EL3_NS() == '0' then
            R(t) = ICC_IGRPEN1_S();
        else
            R(t) = ICC_IGRPEN1_NS();
        end;
    end;
end;
                </pstext>
                </ps>
            </access_permission>
        </access_mechanism>
    
        
        <access_mechanism accessor="MCR ICC_IGRPEN1" type="SystemAccessor">
            <encoding>
            <access_instruction>MCR{&lt;c&gt;}{&lt;q&gt;} &lt;coproc&gt;, {#}&lt;opc1&gt;, &lt;Rt&gt;, &lt;CRn&gt;, &lt;CRm&gt;{, {#}&lt;opc2&gt;}</access_instruction>
                
                <enc n="coproc" v="0b1111"/>
                
                <enc n="opc1" v="0b000"/>
                
                <enc n="CRn" v="0b1100"/>
                
                <enc n="CRm" v="0b1100"/>
                
                <enc n="opc2" v="0b111"/>
            </encoding>
            <access_permission>
                <ps name="MCR" sections="1" secttype="access_permission">
                <pstext>
if !(IsFeatureImplemented(FEAT_AA32EL1) &amp;&amp; IsFeatureImplemented(FEAT_GICv3)) then
    Undefined();
elsif PSTATE.EL == EL0 then
    Undefined();
elsif PSTATE.EL == EL1 then
    if HaveEL(EL3) &amp;&amp; EL3SDDUndefPriority() &amp;&amp; IsFeatureImplemented(FEAT_AA64EL3) &amp;&amp; !ELUsingAArch32(EL3) &amp;&amp; SCR_EL3().IRQ == '1' then
        Undefined();
    elsif HaveEL(EL3) &amp;&amp; EL3SDDUndefPriority() &amp;&amp; IsFeatureImplemented(FEAT_AA32EL3) &amp;&amp; ELUsingAArch32(EL3) &amp;&amp; PSTATE.M != M32_Monitor &amp;&amp; SCR().IRQ == '1' then
        Undefined();
    elsif EL2Enabled() &amp;&amp; IsFeatureImplemented(FEAT_AA64EL2) &amp;&amp; !ELUsingAArch32(EL2) &amp;&amp; HSTR_EL2().T12 == '1' then
        AArch64_AArch32SystemAccessTrap(EL2, 0x03);
    elsif EL2Enabled() &amp;&amp; IsFeatureImplemented(FEAT_AA32EL2) &amp;&amp; ELUsingAArch32(EL2) &amp;&amp; HSTR().T12 == '1' then
        AArch32_TakeHypTrapException(0x03);
    elsif ICC_SRE().SRE == '0' then
        Undefined();
    elsif EL2Enabled() &amp;&amp; IsFeatureImplemented(FEAT_AA64EL2) &amp;&amp; !ELUsingAArch32(EL2) &amp;&amp; ICH_HCR_EL2().TALL1 == '1' then
        AArch64_AArch32SystemAccessTrap(EL2, 0x03);
    elsif EL2Enabled() &amp;&amp; IsFeatureImplemented(FEAT_AA32EL2) &amp;&amp; ELUsingAArch32(EL2) &amp;&amp; ICH_HCR().TALL1 == '1' then
        AArch32_TakeHypTrapException(0x03);
    elsif EL2Enabled() &amp;&amp; IsFeatureImplemented(FEAT_AA64EL2) &amp;&amp; !ELUsingAArch32(EL2) &amp;&amp; HCR_EL2().IMO == '1' then
        ICV_IGRPEN1() = R(t);
    elsif EL2Enabled() &amp;&amp; IsFeatureImplemented(FEAT_AA32EL2) &amp;&amp; ELUsingAArch32(EL2) &amp;&amp; HCR().IMO == '1' then
        ICV_IGRPEN1() = R(t);
    elsif HaveEL(EL3) &amp;&amp; IsFeatureImplemented(FEAT_AA64EL3) &amp;&amp; !ELUsingAArch32(EL3) &amp;&amp; SCR_EL3().IRQ == '1' then
        if EL3SDDUndef() then
            Undefined();
        else
            AArch64_AArch32SystemAccessTrap(EL3, 0x03);
        end;
    elsif HaveEL(EL3) &amp;&amp; IsFeatureImplemented(FEAT_AA32EL3) &amp;&amp; ELUsingAArch32(EL3) &amp;&amp; PSTATE.M != M32_Monitor &amp;&amp; SCR().IRQ == '1' then
        if EL3SDDUndef() then
            Undefined();
        else
            AArch32_TakeMonitorTrapException();
        end;
    elsif HaveEL(EL3) then
        ICC_IGRPEN1_NS() = R(t);
    else
        ICC_IGRPEN1() = R(t);
    end;
elsif PSTATE.EL == EL2 then
    if HaveEL(EL3) &amp;&amp; EL3SDDUndefPriority() &amp;&amp; IsFeatureImplemented(FEAT_AA64EL3) &amp;&amp; !ELUsingAArch32(EL3) &amp;&amp; SCR_EL3().IRQ == '1' then
        Undefined();
    elsif HaveEL(EL3) &amp;&amp; EL3SDDUndefPriority() &amp;&amp; IsFeatureImplemented(FEAT_AA32EL3) &amp;&amp; ELUsingAArch32(EL3) &amp;&amp; SCR().IRQ == '1' then
        Undefined();
    elsif ICC_HSRE().SRE == '0' then
        Undefined();
    elsif HaveEL(EL3) &amp;&amp; IsFeatureImplemented(FEAT_AA64EL3) &amp;&amp; !ELUsingAArch32(EL3) &amp;&amp; SCR_EL3().IRQ == '1' then
        if EL3SDDUndef() then
            Undefined();
        else
            AArch64_AArch32SystemAccessTrap(EL3, 0x03);
        end;
    elsif HaveEL(EL3) &amp;&amp; IsFeatureImplemented(FEAT_AA32EL3) &amp;&amp; ELUsingAArch32(EL3) &amp;&amp; SCR().IRQ == '1' then
        if EL3SDDUndef() then
            Undefined();
        else
            AArch32_TakeMonitorTrapException();
        end;
    elsif HaveEL(EL3) then
        ICC_IGRPEN1_NS() = R(t);
    else
        ICC_IGRPEN1() = R(t);
    end;
elsif PSTATE.EL == EL3 then
    if ICC_MSRE().SRE == '0' then
        Undefined();
    else
        if EffectiveSCR_EL3_NS() == '0' then
            ICC_IGRPEN1_S() = R(t);
        else
            ICC_IGRPEN1_NS() = R(t);
        end;
    end;
end;
                </pstext>
                </ps>
            </access_permission>
        </access_mechanism>

      </access_mechanisms>

      <arch_variants>
      </arch_variants>
  </register>
</registers>
<timestamp>2026-03-26 20:27:25</timestamp>
<commit_id>2026-03_rel</commit_id>
</register_page>