WPF Datagrid edit only single cell value

I have a WPF Datagrid with 2 columns say parametername and value.

My Requirement is only one value(cell content) for a Particular parametername should be editable and the entire Datagrid contents should be read only....

And I have a save button to save the values.

I had been researching from couple of days for an appropriate solution which observes to be a common requirement in many cases but I havent found...

Please any solution or ideas will be appreciated..

Here is XAML & cs : When the Datagrid loads I want only the PM2 cell value to be in edit mode and all other datagrid content should be greyed out or non-editable..

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<Grid>
     <DataGrid ItemsSource="{Binding}"  AutoGenerateColumns="False"
                      Margin="20,57,18,19" Name="dataGrid1" 
                       Height="250" SelectionUnit="Cell" >
 
      <DataGrid.Columns>
      <DataGridTextColumn Binding="{Binding ParameterName}" Width="100"  Header="Parameter     Name"   IsReadOnly="True"/>
 
          <DataGridTextColumn Binding="{Binding Value}" Width="100"  Header="Value" />
 
         </DataGrid.Columns>
 
     </DataGrid>
     </Grid>
 

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And my CS code

public partial class dgSF : Window
 {
 
 ObservableCollection<ParameterSet> pmset;
 
     public dgSF()
     {
         InitializeComponent();
         pmset = new ObservableCollection<ParameterSet>();
 
         pmset.Add(new ParameterSet() { ParameterName = "PM1", Value = 10 });
 
         pmset.Add(new ParameterSet() { ParameterName = "PM2", Value = 50 });
 
         pmset.Add(new ParameterSet() { ParameterName = "PM3", Value = 70 });
 
         pmset.Add(new ParameterSet() { ParameterName = "PM4", Value = 80 });
 
         pmset.Add(new ParameterSet() { ParameterName = "PM5", Value = 100 });
 
         dataGrid1.ItemsSource = pmset;
     }
 }
 
 public class ParameterSet
 {
 
     public string ParameterName { get; set; }
 
     public int Value { get; set; }
 
 }
 

Thanks So much,

Anu

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