Abstract:
A microprocessor system contains a read-only memory (ROM) for storing programs or firmware. Retrieval and execution of program code is controlled by a microprocessor address bus. Erroneous data in the ROM can be corrected by address comparison and translation. Trap, region, and patch tables are provided to store addresses, regions, and translated addresses. An address issued by the microprocessor is stored in the trap and region tables can be translated for selecting another programmable device, such as a SRAM or DRAM, other than the original ROM. Thus, erroneous code in the ROM can be corrected, inserted, or replaced.
Abstract:
The invention provides an electronic apparatus capable of receiving a first-type memory card or a second-type memory card. In one embodiment, the electronic apparatus comprises a socket, a controller circuit, and an interface circuit. The socket is coupled to the first-type memory card through a set of first pins and is coupled to the second-type memory card with a set of second pins. The controller circuit accesses the first-type memory card or the second-type memory card via a plurality of input/output (IO) pins, and determines which of the first-type memory card and the second-type memory card is inserted into the socket according to the voltage of a target IO pin selected from the IO pins. The interface circuit sets the voltage of the target pin to different values according to whether the first-type memory card or the second-type memory card is inserted into the socket.