<?xml version='1.0' encoding='utf-8'?>
<!DOCTYPE register_page SYSTEM "registers.dtd">
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<register_page>
  <registers>
  
    <register is_register="True" is_internal="False" is_stub_entry="False">
      <reg_short_name>CNTTIDR</reg_short_name>
        
        <reg_long_name>Counter-timer Timer ID Register</reg_long_name>

        <power_domain_text>It is <arm-defined-word>IMPLEMENTATION DEFINED</arm-defined-word> whether CNTTIDR is implemented in the Core power domain or in the Debug power domain</power_domain_text>


      
      

    
  <reg_address
      external_access="False"
    mem_map_access="True"
      power_domain="None"
  >
    <reg_component>Timer</reg_component>
    <reg_frame>CNTCTLBase</reg_frame>
    <reg_offset><hexnumber>0x008</hexnumber></reg_offset>
    <reg_instance>CNTTIDR</reg_instance>
    <reg_access>
      
        
      <reg_access_state>
          <reg_access_type>RO</reg_access_type>
      </reg_access_state>
    </reg_access>
</reg_address>



          <reg_reset_value></reg_reset_value>

      <reg_mappings>
        




      </reg_mappings>

        <reg_purpose>
          
    
      <purpose_text>
        <para>Indicates the implemented timers in the physical address space, and their features. For each value of N from 0 to 7 it indicates whether:</para>

      </purpose_text>
      <purpose_text>
        <list type="unordered">
<listitem><content>Frame CNTBaseN is a view of an implemented timer.</content>
</listitem><listitem><content>Frame CNTBaseN has a second view, CNTEL0BaseN.</content>
</listitem><listitem><content>Frame CNTBaseN has a virtual timer capability.</content>
</listitem></list>
      </purpose_text>

        </reg_purpose>

      <reg_groups>
          <reg_group>Timer</reg_group>
      </reg_groups>
      <reg_configuration>
        
    
      <configuration_text>
        <para>For more information, see <xref linkend="#CEGHAIAF">'Power and reset domains for the system level implementation of the Generic Timer'</xref>.</para>
      </configuration_text>

      </reg_configuration>
      
      
        
      <reg_attributes>
          
    
      <attributes_text>
        <para>CNTTIDR is a 32-bit register.</para>
      </attributes_text>

      </reg_attributes>
      <reg_fieldsets>
        






<fields id="fieldset_0" length="32">
  <text_before_fields/>
  <field id="fieldset_0-31_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>Frame&lt;n&gt;</field_name>
    <field_msb>31</field_msb>
    <field_lsb>0</field_lsb>
    <rel_range>31:0</rel_range>
    <field_description order="before"><para>A 4-bit field indicating the features of frame CNTBase&lt;n&gt;.</para>
<para>Bit[3] of the field is <arm-defined-word>RES0</arm-defined-word>.</para>
<para>Bit[2], the FEL0 subfield, indicates whether frame CNTBase&lt;n&gt; has a second view, CNTEL0Base&lt;n&gt;. The possible values of this bit are:</para>
<table><tgroup cols="2"><thead><row><entry>Bit[2]</entry><entry>Meaning</entry></row></thead><tbody><row><entry><binarynumber>0b0</binarynumber></entry><entry>Frame&lt;n&gt; does not have a second view. The <register_link state="ext" id="ext-cntel0acr.xml">CNTEL0ACR</register_link> register in the first view of the frame is <arm-defined-word>RES0</arm-defined-word>.</entry></row><row><entry><binarynumber>0b1</binarynumber></entry><entry>Frame&lt;n&gt; has a second view, CNTEL0Base&lt;n&gt;.</entry></row></tbody></tgroup></table>
<para>If bit[0] is 0, bit[2] is <arm-defined-word>RES0</arm-defined-word>.</para>
<para>Bit[1], the FVI subfield, indicates whether both:</para>
<list type="unordered">
<listitem><content>Frame CNTBase&lt;n&gt; implements the virtual timer registers <register_link state="ext" id="ext-cntv_cval.xml">CNTV_CVAL</register_link>, <register_link state="ext" id="ext-cntv_tval.xml">CNTV_TVAL</register_link>, and <register_link state="ext" id="ext-cntv_ctl.xml">CNTV_CTL</register_link>.</content>
</listitem><listitem><content>This CNTCTLBase frame implements the virtual timer offset register <register_link state="ext" id="ext-cntvoffn.xml">CNTVOFF&lt;n&gt;</register_link>.</content>
</listitem></list>
<para>The possible values of bit[1] are:</para>
<table><tgroup cols="2"><thead><row><entry>Bit[1]</entry><entry>Meaning</entry></row></thead><tbody><row><entry><binarynumber>0b0</binarynumber></entry><entry>Frame&lt;n&gt; does not have virtual capability. The virtual time and offset registers are <arm-defined-word>RES0</arm-defined-word>.</entry></row><row><entry><binarynumber>0b1</binarynumber></entry><entry>Frame&lt;n&gt; has virtual capability. The virtual time and offset registers are implemented.</entry></row></tbody></tgroup></table>
<para>If bit[0] is 0, bit[1] is <arm-defined-word>RES0</arm-defined-word>.</para>
<para>Bit[0], the FI subfield, indicates whether frame CNTBase&lt;n&gt; is implemented. The possible values of this bit are:</para>
<table><tgroup cols="2"><thead><row><entry>Bit[0]</entry><entry>Meaning</entry></row></thead><tbody><row><entry><binarynumber>0b0</binarynumber></entry><entry>Frame&lt;n&gt; is not implemented. All registers associated with the frame are <arm-defined-word>RES0</arm-defined-word>.</entry></row><row><entry><binarynumber>0b1</binarynumber></entry><entry>Frame&lt;n&gt; is implemented.</entry></row></tbody></tgroup></table></field_description>
    <field_array_indexes index_variable="n" element_size="4" range_specifier="4n+3:4n">
      <field_array_index>
        <field_array_start>7</field_array_start>
        <field_array_end>0</field_array_end>
      </field_array_index>
    </field_array_indexes>
  </field>
  <text_after_fields/>
</fields>




<reg_fieldset length="32">
  <fieldat id="fieldset_0-31_0" label="Frame7" msb="31" lsb="28"/>
  <fieldat id="fieldset_0-31_0" label="Frame6" msb="27" lsb="24"/>
  <fieldat id="fieldset_0-31_0" label="Frame5" msb="23" lsb="20"/>
  <fieldat id="fieldset_0-31_0" label="Frame4" msb="19" lsb="16"/>
  <fieldat id="fieldset_0-31_0" label="Frame3" msb="15" lsb="12"/>
  <fieldat id="fieldset_0-31_0" label="Frame2" msb="11" lsb="8"/>
  <fieldat id="fieldset_0-31_0" label="Frame1" msb="7" lsb="4"/>
  <fieldat id="fieldset_0-31_0" label="Frame0" msb="3" lsb="0"/>
</reg_fieldset>


      </reg_fieldsets>

      <access_mechanisms>
          


  
    
      <access_permission_text>
        <para>In a system that supports the Realm Management Extension, it is <arm-defined-word>IMPLEMENTATION DEFINED</arm-defined-word> whether Root and Realm accesses to this register are permitted. If not permitted, this register behaves as <arm-defined-word>RES0</arm-defined-word> for Root and Realm accesses.</para>

      </access_permission_text>
      <access_permission_text>
        <para>In a system that recognizes two Security states, this register is accessible by both Secure and Non-secure accesses.</para>
      </access_permission_text>





    

      </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>