Error judgment method

Claim 1

A method of judging a data memory access error in an information processing apparatus capable of accessing a data memory different from a main memory for storing operation control software, and having a plurality of operation levels for executing processes associated with interruption processing and a set of general registers arranged in units of operation levels to switch processes by an interruption operation, comprising the steps of: setting a data memory access error flag in the process state register upon occurrence of a data memory access error, and holding the data memory access error flag in the process state register until updating of the process state register when the operation level is changed by an interruption operation or until executing a software instruction of read and clear the process state register; storing the data memory access error flag in one of the general registers in units of operation levels at the occurrence of an operation level change from a first operation level to a second operation level; reloading the process state register from the general registers after the first operation level is resumed; and judging that an access error has occurred upon detection of the error flag in the process state register that read the instruction of read and clearing the process state register.

Claim 2

A method of judging a data memory access error in an information processing apparatus capable of accessing a data memory different from a main memory for storing operation control software, and having a plurality of operation levels for executing processes associated with interruption processing and a set of general registers arranged in units of operation levels to switch processes by an interruption operation, comprising the steps of: setting a data memory access error flag in the process state register upon occurrence of a data memory access error, and holding the data memory access error flag in the process state register until updating of the process state register when the operation level is changed by an interruption operation or until executing a software instruction of read and clear the process state register; storing the data memory access error flag in one of the general registers in units of operation levels at the occurrence of an operation level change from a first operation level to a second operation level; reloading the process state register from the general registers after the first operation level is resumed; and judging that an access error has occurred upon detection of the error flag in the process state register that read the instruction of read and clearing the process state register.