JPH02220132A - Cpu type deciding device - Google Patents

Abstract

PURPOSE:To omit a set state changing operation by deciding the type of a CPU through the comparison carried out between the measured executing time and the executing time stored in a decision table. CONSTITUTION:A CPU type deciding means 54 decides the type of a CPU by comparing the executing time measured by a loop executing time measuring means 52 with the executing time stored in a decision table 80. That is, the executing time of a loop executing means 50 varies with the change of the frequency of a basic control clock 12. A timer 14 can measure the executing time regardless of the frequency of the clock 12. Thus the CPU type is decided by comparing the executing time measured by the means 52 with that stored in the table 80. As a result, a CPU type deciding device is obtained with no addition of circuits nor any operation required for change of the CPU type just by preparing those means 50, 52 and 54, and the table 80 in a form of firmware.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention has the same basic operation, but the highest frequency of the basic operation clock that can operate (hereinafter referred to as CPU type).
The present invention relates to a CPU type discriminating device for a computer system in which multiple types of CPUs having different types can be used.

[Conventional technology]

CPU (Central Processing Unit) of a computer system
When integrating as one to several microprocessors,
There is generally a trade-off between operating speed and price. In that case, it is possible to prepare several types of chips that have the same basic operation, that is, most or all of the instruction set, but differ in the maximum operating frequency of the clock, and select and use them according to the purpose of use. often done. At this time, the hardware surrounding the CPU can be prepared for a change in CPU type by simply changing the frequency of the basic operating clock by replacing the unit. However, as software, it is necessary to realize the difference in purpose of use, that is, the difference in whether or not to input and output data with 110 devices that require high-speed processing. Information must be input to the CPU.

[Problem to be solved by the invention]

Conventionally, in order to realize this, it was necessary to add a circuit such as a changeover switch, and when changing the clock frequency, it was also necessary to change the changeover switch.

Therefore, it is an object of the present invention to provide a CPU type determination device that does not require circuit changes or settings changes.

[Means to solve the problem]

FIG. 1 is a diagram showing the basic configuration of a CPU type discriminating device according to the present invention. In the figure, the CPU type discriminating device of the present invention has a basic control clock 12 whose frequency can be changed according to the type of CPU 10, and a basic control clock 12 that operates in real time.
A CPU type discriminating device for a computer system comprising a timer 14 accessible from zero, the loop execution device executing a predetermined number of loops consisting of control instructions for the CPU 10 based on the basic control clock 12. means 50, and the loop execution means 50 by the timer 14.
loop execution time measuring means 52 for measuring the execution time of;
A determination table 80 that stores the relationship between execution time and CPU type is used to compare the execution time measured by the execution time measuring means 52 with the execution time in the determination table 80 to determine whether the CPU
This is characterized by comprising a CPU type determining means 54 for determining the type.

[For production]

When the frequency of the basic control clock 12 changes, the execution time of the loop execution means 50 changes. Since the timer 14 can measure real time regardless of the frequency of the basic control clock 12, if the execution time measured by the loop execution time measuring means 52 is compared with the time in the discrimination table 80, the CPU
The type is determined. By incorporating the loop execution means 50, the loop execution time measurement means 52, the CPU type determination means 54, and the discrimination table 80 in the form of firmware, the CPU can be used without adding any circuits or requiring any operation to change the CPU type. A type discrimination device is implemented.

〔Example〕

FIG. 2 is a block diagram of a computer system incorporating an embodiment of the CPU type discriminating device according to the present invention.

CPU10I consists of a microprocessor with integrated directly accessible registers 102.

The control clock unit 121 supplies a control clock to the CPUI0I, and can be replaced depending on the type of CPUIOL. ROM501 contains execution time and C
Data representing the relationship with the PU type and a software program to be described later are encoded and stored. R
The AM 103 stores control data, processing data, and the like. Timer 141 measures real time. These cpυ101, ROM501, RAM103
, and timer 141 are mutually connected by an internal bus 110, and can be accessed by other units from CPU10I.

FIG. 3 is a flowchart of software stored in the ROM 501 to implement the loop execution means 50, loop execution time measurement means 52, and CPU type determination means 54 described above. When CPUl0I starts processing, a series of these processes is executed in the form of initial processing. First, the timer 14 is set to an initial value of 0 (step a), a predetermined number of loops are started (step b), and when the predetermined number of loops are completed, the value of the timer 14 is read (step C) and stored in the ROM 501. Compare with the value in the stored discrimination table (step d) Since the time required for each type of CPU to execute the predetermined number of times is stored in the 0 discrimination table, the actual value of the timer 14 is The CPU type can be determined from the value. Once the code representing the determined CPU type is stored in the register 102 (step e), normal processing begins.

〔Effect of the invention〕

As described above, according to the present invention, there is no need to change or add circuits, and there is no need to change the settings of the CPU.
A typing device is provided.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the principle configuration of the present invention, FIG. 2 is a block diagram of hardware in an embodiment of the invention, and FIG. 3 is a flowchart of software in an embodiment of the invention. In the figure, 12...Basic control clock, 121...II? illiotsuku unit. Second

Claims (1)

[Claims] 1. For a computer system comprising a basic control clock (12) whose frequency can be changed depending on the type of CPU (10) and a timer (14) that operates in real time and is accessible from the CPU (10). A CPU type discriminating device, comprising: a CPU type determination device based on the basic control clock (12);
loop execution means (50) for executing a predetermined number of loops consisting of control instructions; loop execution time measuring means (52) for measuring the execution time of the loop execution means (50) using the timer (14); A discrimination table (80) that stores the relationship between time and CPU type, and a CPU type is determined by comparing the execution time measured by the execution time measuring means (52) with the execution time in the discrimination table (80). A CPU type discriminating device comprising: CPU type determining means (54).