When in a debug session, use the Registers view to display and modify the register values on the connected target. To display the Registers view in the Debug perspective, click on the menu.

The Registers view displays the MCU registers arranged in categories. To display the values of a particular category of registers, expand the respective tree node in the view.
To change the format of the register value, right-click the register in the view and click Number format and the preferred format on the context menu. You can choose between the hex, octal, decimal, or binary format.