JPH04299717A - Electronic equipment - Google Patents

Abstract

PURPOSE:To eliminate the need for setting a control register, etc., or switching a BIOS for a personal computer wich can work with plural types of operating frequency by judging the operating frequency. CONSTITUTION:When a power supply is turned on, the count (n) is set at 0. Thereafter a program loop which actually performs nothing to the outside is repeated together with the processing which adds 1 to the count (n) until the set time is counted up by a clock circuit. When the count (n) satisfies a<=n<=b at the set time, the operating frequency is judged as 9.6MHz and then as 16MHz if c<=n<=d is satisfied respectively. Furthermore the operating frequency is judged as 25MHz if the count (n) satisfies e<=n<=f. Thus various setting operations are carried out to each controller based on those decided operating frequency levels. That, is a<=b<c<=d<e<=f is satisfied. Then the normal operation processing sets in after various setting operations requiring each operating frequency are carried out.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic device that is provided with a plurality of oscillators each supplying a different operating frequency, and that operates at one of the operating frequencies.

0002

[Prior Art] Conventionally, for example, a DRAM controller was
In a system controlled by a PU (central processing unit), the CPU
In order to properly control a DRAM controller, it is necessary to make various settings in the DRAM controller in relation to the operating frequency supplied to the CPU.

[0003] If the operating frequency setting in the DRAM controller is different from the operating frequency actually supplied to the CPU, the DRAM controller
Access to RAM cannot be controlled correctly.

[0004] Therefore, the BIOS (b
Asic I/O system) is written with processing to perform various settings for control devices such as DRAM controllers that need to be set according to the operating frequency when the power is turned on, based on a preset operating frequency. .

Recently, while there has been a demand for faster processing speeds, there has also been a problem with compatibility with conventional software. It can also be used at conventional operating frequencies.

In other words, it is equipped with an oscillator that generates an increased operating frequency to increase processing speed and an oscillator that generates a conventional operating frequency, and a plurality of ROMs each having a BIOS corresponding to each operating frequency. It is equipped.

[0007] In such a personal computer,
When selecting an oscillator using a dip switch or the like to switch to a desired operating frequency, set the control register etc. using a dip switch or the like to correspond to the operating frequency, or set the ROM containing the BIOS to correspond to the operating frequency. I was switching.

[0008]

[Problem to be Solved by the Invention] Conventionally, each time the operating frequency is changed, the operating frequency currently being supplied to the CPU is checked, and a control register or the like is set using a dip switch or the like in accordance with the operating frequency. Furthermore, there is a problem in that it is necessary to switch to a ROM equipped with a BIOS that corresponds to the operating frequency.

Therefore, the present invention provides an electronic device that does not require setting a control register or switching the BIOS according to the operating frequency when switching the operating frequency in a personal computer or the like that can be used at multiple operating frequencies. The purpose is to provide

0010

[Means for Solving the Problems] The present invention provides a clock circuit for measuring time, a plurality of oscillators each supplying a different operating frequency, and one oscillator selected from the plurality of oscillators. Consisting of a central processing unit that operates at an operating frequency and multiple control units controlled by this central processing unit, the central processing unit is a loop that repeatedly performs loop processing until the clock circuit measures a preset time. A processing means, a counting means for counting the number of times of processing by the loop processing means, an operating frequency being determined based on the number of times counted by the counting means, and various settings for each control device being made based on the operating frequency value. An operating frequency setting means is provided.

[0011]

[Operation] In the present invention having such a configuration, the loop processing means repeats the loop processing until the clock circuit measures the set time.

The counting means counts the number of times the loop processing has been performed, and when a set time has elapsed, the operating frequency setting means determines the operating frequency supplied to the central processing unit based on the counted number of times. , various settings for each control device are performed based on the operating frequency value.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, 1 is a CPU (central processing unit) constituting the main body of the control section, and 2 is a clock circuit. ROM (read only memory) 3 is a BIOS (basic I/O system) that has settings related to operating frequency.
tem) is formed, and program data for processing performed by the CPU 1 is stored. A RAM (random access memory) 4 is formed with a counter "n" and various memory areas used when the CPU 1 performs processing.

[0015] The CPU 1 includes the clock circuit 2, the ROM
3 and RAM 4 by a system bus 5, and signals are controlled by a bus controller 6.

DIP switch 7 has oscillators 8, 9, 10
One of the oscillators is connected to the CPU1.

A DRAM (dynamic random access memory) controller 11 controls access to a DRAM 12 as an extended RAM.

The peripheral control device 13 is another controller or interface.

FIG. 2 shows a flowchart of the processing performed by the CPU 1 when the power is turned on.

First, when the power is turned on, the counter "n"
” to 0.

Thereafter, the clock circuit 2 checks the time and adds +1 to the counter "n" in a program loop that does not actually do anything to the outside until the time reaches the set time. The process is repeated.

(Loop processing means, counting means) When the set time elapses, if the count n at that time satisfies a≦n≦b, the operating frequency is determined to be 9.6 MHz,
Based on its operating frequency, the bus controller 6, DR
Various settings are made for the AM controller 11 and peripheral control device 13 that require settings based on operating frequency.

Note that the relationship is a≦b<c≦d<e≦f.

Further, if the count n satisfies c≦n≦d, the operating frequency is determined to be 16 MHz, and the operating frequency of the bus controller 6, DRAM controller 11, and peripheral control device 13 is determined based on the operating frequency. Configure various settings for items that require settings.

Furthermore, if the count n satisfies e≦n≦f, the operating frequency is determined to be 25 MHz, and the operating frequencies of the bus controller 6, DRAM controller 11, and peripheral control device 13 are determined based on the operating frequency. Configure various settings for items that require settings. (Operating Frequency Setting Means) Furthermore, if the count n does not satisfy any of a≦n≦b, c≦n≦d, or e≦n≦f, the process returns to the beginning.

After the operating frequency is determined, the bus controller 6
, the DRAM controller 11 and the peripheral control device 13 that require settings based on the operating frequency, and then proceed to normal operation processing.

In this embodiment with such a configuration, the CP
The operating frequency supplied to U1 is set by dip switch 7.

Incidentally, the time required for processing such as a program loop varies depending on the operating frequency, and as a result, the count of the counter "n" when the set time has elapsed differs depending on each operating frequency.

Therefore, the operating frequency set by the dip switch 7 is determined from the count of the counter, and the operating frequency value obtained by this determination is used to control the bus controller etc. that requires setting based on the operating frequency.
Various settings are automatically performed.

As described above, according to this embodiment, the operating frequency selected by the DIP switch is automatically determined and recognized, and various settings are performed for peripheral control devices that require settings based on the operating frequency. become. Therefore, there is no need to operate a dip switch for setting a control register or to switch a ROM in which a BIOS is provided when the operating frequency is changed.

Furthermore, one BIOS can automatically perform various settings for peripheral control devices in accordance with a plurality of operating frequencies.

[0032]

[Effects of the Invention] As detailed above, according to the present invention,
When switching the operating frequency on a personal computer that can be used with multiple operating frequencies, it is necessary to set the control register according to the operating frequency, or set the BI
It is possible to provide electronic equipment that does not require changing the OS.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIG. 2 is a flowchart showing the same embodiment.

[Explanation of symbols]

1...CPU, 2...Clock circuit, 3...ROM (BIOS),
4...RAM (counter), 7...Dip switch, 8,
9,10...oscillator.

Claims (1)

[Claims] Claim 1: A clock circuit that measures time, a plurality of oscillators each supplying a different operating frequency, and a central processing unit that operates at the operating frequency supplied by one oscillator selected from the plurality of oscillators. and a plurality of control devices controlled by this central processing unit, and the central processing unit includes a loop processing means for repeatedly performing loop processing until the clock circuit measures a preset time; a counting means for counting the number of times of processing by the processing means; and an operating frequency setting means for determining an operating frequency based on the number of times counted by the counting means and making various settings for each of the control devices based on the operating frequency value. An electronic device characterized by being provided with.