By default, the source panel and the disassembly panel each take up half the space of the ARM Workbench editor, but you can adjust this proportion by clicking and dragging the line that divides the two panels.

To see either the source or the disassembly panel exclusively, use the button, located in the menu bar of the code view By default, this is set to Source & Disassembly, but you can press the button to cycle to the Source Only or Disassembly Only to see one of the views exclusively. Use the small arrow to the right of the button to open a drop-down menu and select any of these options directly.