A protective apparatus communicatively coupled to an indirect access memory controller associated with a memory , comprising: a bus monitoring unit configured to monitor a memory access request having a bus address and to detect a register controlling operation; and a window register unit configured to receive an operation address from the bus monitoring unit based on the register controlling operation and to select an access type of different access types based on the received operation address, wherein the bus monitoring unit is configured to monitor the bus address and detect the register controlling operation when the memory access request is for configuring the sent operation address of different access types stored in the window register unit , and when a register controlling operation is detected: the bus monitoring unit is configured to initiate an authentication by sending the bus address from the memory access request to a permission list unit ; the window register unit is configured to send as part of the authentication the selected access type of a corresponding window register as an address to the permission list unit ; and the permission list unit is configured to receive the bus address from the bus monitoring unit and the selected access type from the window register unit , and to authenticate the bus address by evaluating the bus address according to a permission list and selected access type and determining from the permission list a permission attribute that corresponds to the bus address. a bus monitoring unit configured to monitor a memory access request having a bus address and to detect a register controlling operation; and a window register unit configured to receive an operation address from the bus monitoring unit based on the register controlling operation and to select an access type of different access types based on the received operation address, wherein the bus monitoring unit is configured to monitor the bus address and detect the register controlling operation when the memory access request is for configuring the sent operation address of different access types stored in the window register unit , and when a register controlling operation is detected: the bus monitoring unit is configured to initiate an authentication by sending the bus address from the memory access request to a permission list unit ; the window register unit is configured to send as part of the authentication the selected access type of a corresponding window register as an address to the permission list unit ; and the permission list unit is configured to receive the bus address from the bus monitoring unit and the selected access type from the window register unit , and to authenticate the bus address by evaluating the bus address according to a permission list and selected access type and determining from the permission list a permission attribute that corresponds to the bus address. the bus monitoring unit is configured to initiate an authentication by sending the bus address from the memory access request to a permission list unit ; the window register unit is configured to send as part of the authentication the selected access type of a corresponding window register as an address to the permission list unit ; and the permission list unit is configured to receive the bus address from the bus monitoring unit and the selected access type from the window register unit , and to authenticate the bus address by evaluating the bus address according to a permission list and selected access type and determining from the permission list a permission attribute that corresponds to the bus address. <EOS>