void clearRegisterValues(ProgramLocationActionContext context) {
		Register register = getRegister(context);
		AddressSetView addrSet = getAddressSet(context);
		if (register == null) {
			register = registerMgrProvider.getSelectedRegister();
		}
		SetRegisterValueDialog dialog =
			new SetRegisterValueDialog(context.getProgram(), registers, register, addrSet, false);

		tool.showDialog(dialog);

		Register selectedRegister = dialog.getSelectRegister();
		if (selectedRegister != null) {
			applyRegisterValues(context.getProgram(), selectedRegister, null, addrSet);
		}
	}
Shows the registers available in a program along with any values that are set.
Ghidra/Features/Base/src/main/java/ghidra/app/plugin/core/register/RegisterPlugin.java