Abstract: A bus control device having a plurality of devices such as a processor or a DMAC which can be a bus master accessing a system bus. When the processor transfers data to a memory or a processing circuit, a system bus controller for the processor and a system bus controller for the memory or a system bus controller for the processing circuit access the system bus within an accessible minimum time with each of input/output signals. When the DMAC transfers data to the memory or the processing circuit, a system bus controller for the DMAC and the system bus controller for the memory or the system bus controller for the processing circuit access the system bus within the accessible minimum time with each of the input/output signals.

Abstract: A bus control device having a plurality of devices such as a processor or a DMAC which can be a bus master accessing a system bus. When the processor transfers data to a memory or a processing circuit, a system bus controller for the processor and a system bus controller for the memory or a system bus controller for the processing circuit access the system bus within an accessible minimum time with each of input/output signals. When the DMAC transfers data to the memory or the processing circuit, a system bus controller for the DMAC and the system bus controller for the memory or the system bus controller for the processing circuit access the system bus within the accessible minimum time with each of the input/output signals.

Abstract: There is provided an online program-updating system which is capable of updating contents of a program without interrupting any services provided by the system. A management information storage section stores management information including operative status flags each indicative of the operative status of a corresponding program module and information of a version number associated with the corresponding program module. A program execution section updates operative status flags based on the operative statuses of the program modules. A version number check section makes a comparison between the version number of each program module of a revised program and that of each program module of the existing program in response to a download request, and determines that an update of the program is required, if the version number of the program module of the revised program is newer.

Abstract: A firmware trace data acquisition method is constituted such that there are provided a monitoring part for monitoring firmware processes and a DMA part for transferring data to a trace data storing part in accordance with an instruction from the monitoring part, such that labels are attached to the plurality of process modules stored in a firmware storing part, and such that each of the process modules activated notifies the monitoring part of the label attached to itself. The monitoring part latches the label that it is notified of and monitors the execution of the corresponding process such that, when an abnormality is detected during the execution, the monitoring part controls the DMA part so as to transfer detailed data, derived from the process module corresponding to the label latched, to the trace data storing part, and such that, when there is no abnormality detected, the monitoring part allows the DMA part to transfer the latched label to the trace data storing part.