JPS6175437A - Interruption processing system - Google Patents

Abstract

PURPOSE:To maintain an old mode without requiring any mode by providing a data processor with plural interruption execution modes and initiating only interruption from a low-level execution mode to a high-level execution mode when interruption occurs. CONSTITUTION:When the execution mode in current operation is changed to another mode, registers 1 and 2 are stored with the current execution mode and old mode. Namely, if a microprogram is interrupted, the mode in operation is moved from the register 1 and held in a register 2 and the mode of interruption generation processing contents is held in the register 1. If there is an interruption factor, an interruption control part 7 compares the expected interruption mode with the current execution mode to allow the interruption when the former is higher in level than the latter or inhibit the interruption when not. When the expected interruption mode is higher in level than the current execution mode, the interruption is initiated, the contents of the register 1 are moved to the register 2, and the expected interruption mode is stored in the register 1.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an interrupt processing method in a data processing device using a microprogram control method.

Microprogram control type data processing devices are widely used because the functions of machine instructions can be changed only by changing the microprogram without changing the hardware, and the changes are easy. Moreover, the logic circuit of this data processing device is simplified, and reliability is improved.

The data processing device stores the above microprogram in a control storage. In order to improve the operational efficiency of data processing devices, it is necessary that interrupt processing for microprograms be performed efficiently, and therefore, an efficient interrupt processing method is desired.

[Conventional technology]

In the microprogram-controlled data processing device described above, when an interrupt occurs to the microprogram, a flag indicating which type of interrupt processing is to be performed is sent at the beginning of the interrupt processing routine. This flag allows the status of the current process to be detected.

When performing this interrupt processing, if it is desired to prohibit other types of interrupts, the data processing device provides a mask bit in the microinstruction or a mask register, and displays prohibition there. Furthermore, access to new and old status information during an interrupt is not subject to memory protection, and it is necessary for the microprogram to issue a non-protection instruction to access information that is not subject to memory protection. Ta. That is,
When an interrupt occurs, the microprogram needs to instruct each corresponding part to be protected or unprotected.

[Problem that the invention seeks to solve]

In the conventional interrupt processing method described above, when it is desired to disable other types of interrupts, each microprogram issues instructions for disabling each type of interrupt, which not only complicates the creation of a microphone program (but also requires masking in microinstructions). There was a problem with the need for bits and mask registers.

[Means for solving problems]

The present invention provides an efficient microprogram interrupt processing method for a microprogram-controlled data processing device that solves the above-mentioned problems. The means is
In a data processing device in which a microprogram is stored in a control storage, the data processing device is provided with a plurality of interrupt execution modes, and is provided with means for storing the current mode and the old mode at the time of interrupt occurrence. In this case, the transition from the lower execution mode to the upper execution mode of the table is performed by an interrupt, the transition from the upper execution mode to the lower execution mode is controlled by the actual execution mode, and the means for storing the old mode is controlled by a microcontroller. This is done using an interrupt processing method that can be read by a program.

[Effect]

This is achieved by providing a data processing device with a plurality of interrupt execution modes, executing only the execution mode from the lower level to the upper level execution mode by interrupt when an interrupt occurs, and making the means for storing the old mode readable.

〔Example〕

Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram of an interrupt processing method according to the present invention,
FIG. 2 is a flow chart of the present invention.

Each data processing device has a mode defined for each processing content. (Modes and processing details will be described later) Registers 1 and 2 are provided as a means to store the actual execution mode and old mode when the currently operated execution mode is transferred to another mode. be. That is, when an interrupt occurs to the microprogram, the operating mode is transferred from register 1 and held in register 2,
The mode of the interrupt generation processing content is held in register 1.

The control storage 4 is searched with the address of the address register 3 which holds the address for calling the control storage microprogram. Note that the lower the number, the higher the level in the table.

If a table interrupt cause exists, the interrupt control unit 7 compares the mode in which the interrupt should be made and the actual execution mode depending on the cause, and if the mode to be interrupted is higher than the actual execution mode, an interrupt occurs, and If it is low, no interrupt will occur.

If the mode to be interrupted is higher than the actual mode, an interrupt is generated, the contents of the actual mode register 1 are transferred to the old mode register 2, and the new mode to be interrupted is placed in the actual mode register 1. At the same time, the start address of the interrupt process is entered into the address register 3. Since interrupts are controlled according to the execution mode level in this way, no masking is required.

Execution conditions such as memory protection are determined by the execution condition control unit 8.
With reference to the actual execution mode, control is performed such that, for example, level 9 is treated as a protection target, and levels O to 8 are not protected.

A method for realizing this execution condition control section 8 using a storage device is explained in the second section.
This will be explained using figures. A storage device 9 whose address is the actual execution mode is provided, and each output bit of the storage device 9 controls functions such as storage protection. In the case of the storage device 9, the contents are undefined immediately after the power is turned on and must be initialized using a microprogram, but it also has the flexibility of being able to change the contents using a microprogram if necessary.

Note that the target to be controlled by the execution condition control unit is not limited to memory protection, and can be applied to any target that requires different control depending on the level.

〔Effect of the invention〕

As explained above, according to the present invention, interrupts to microprograms do not require masks, improving efficiency, making it easier to create microprograms, and preserving the old mode. It can be used to investigate the cause when a check occurs, and has many advantages in analyzing equipment operational failures.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an interrupt processing method according to the present invention, and FIG. 2 is a block diagram when execution conditions are determined by a storage device. In the figure, l and 2 represent registers, and 4 represents control storage, respectively.

Claims (2)

[Claims] (1) In a data processing device in which a microprogram is stored in a control storage, the data processing device is provided with a plurality of interrupt execution modes and means for storing the current mode and the old mode at the time of occurrence of the interrupt. When an interrupt occurs, the transition from the lower execution mode to the higher execution mode is performed by the interrupt, and the transition from the upper execution mode to the lower execution mode is performed by a microprogram in the actual execution mode, and the execution conditions are set in the actual execution mode. An interrupt processing method characterized by control. (2) The method for controlling the execution conditions by the actual execution mode is characterized in that the actual execution mode is used as an address, storage means for storing the execution conditions is provided, and the storage means can be initialized and changed by a microprogram. An interrupt processing method according to claim 1.