Information processing apparatus for executing application programs under control of a system program

Claim 1

An information processing apparatus for executing a plurality of application programs under control of a system program, comprising: memory means for storing said system program; context blocks storing means for storing a plurality of context blocks, each of said plurality of context blocks corresponding respectively to a context of one of said plurality of application programs; system control means including a system program executing means for controlling execution of said plurality of application programs; load pointing means for pointing out an address of one of said plurality of context blocks under control of said system program executed in said system control means, said address of said one of said context blocks pointed out by said load pointing means being replaced with an address of a context block corresponding to a next one of said application programs, when said next one of said application programs is determined to be executed, under control of said system program executed in said system control means; and application program executing means, connected to said system program executing means through a swap in line and a swap out line, for executing said application program corresponding to said context block whose address is pointed out by said load pointing means, said application program being executed until said next one of said application programs is determined in said system control means and being replaced with said next one of said application programs, said application program executing means including; a register for registering an address of said context block pointed out by said load pointing means; and an internal state memory for storing said context stored in said context block whose address is registered in said register; wherein said system control means generates a swap-in request signal and a swap-out request signal along said swap-in line and said swap-out line, respectively, said swap-in request signal indicating a request for writing a context stored in said context block pointed out by said load pointing means to said internal state memory, and said swap-out request signal indicating a request for writing a context stored in said internal state memory to said context block pointed out by said load pointing means.

Claim 8

A method for controlling execution of a plurality of application programs in an information processing system including a system processor, an application processor connected to said system processor via a swap-in line and a swap-out line, and a memory connected to said system processor and said application processor, said method comprising the steps of: providing in said memory a plurality of context blocks; storing in each of said plurality of context blocks context information consisting of processor status information respectively corresponding to said plurality of application programs; indicating under control of said system processor a particular context block corresponding to a particular application program to be executed; loading into an internal memory of said application processor particular context information stored in said particular context block in response to a swap-in command from said system processor; executing said particular application program in said application processor; pointing under control of said system processor to a new context block corresponding to a new application program to be executed; swapping-out current context information stored in said internal memory and replacing context information stored in said particular context block with said current context information as suspended context information in response to a swap-out command from said system processor; and loading into said internal memory new context information from said new context block for processing said new application program to be executed.

Claim 9

A method for controlling execution of a plurality of application programs in an information processing system including a system processor, an application processor connected to said system processor via a swap-in line and a swap-out line, and a memory connected to said system processor and said application processor, said method comprising the steps of: providing in said memory a plurality of context blocks; storing in each of said plurality of context blocks context information consisting of processor status information respectively corresponding to said plurality of application programs; indicating under control of said system processor a particular context block corresponding to a particular application program to be executed; loading into an internal memory of said application processor particular context information stored in said particular context block in response to a swap-in command from said system processor; executing said particular application program in said application processor; pointing under control of said system processor to a new context block corresponding to a new application program to be executed; swapping-out current context information stored in said internal memory and replacing context information stored in said particular context block with said current context information as suspended context information in response to a swap-out command from said system processor; and loading into said internal memory new context information from said new context block for processing said new application program to be executed.