JPS5935266A - Display system for memory contents - Google Patents

Abstract

PURPOSE:To eliminate a misread and trouble of the memory display of an electronic equipment by controlling the switching of the contents of a memory, if necessary. CONSTITUTION:When the memory display selection key 8A of a key input device 8 is pressed, the state of a flag M provided in the memory 6 is inverted. The decision is made that the contents of the register E in the memory 6 are displayed at the lower stage of the display or that lower stage of the display is placed in a blanking state, according to the contents of the flag M. Then, the contents of a D register are decoded to display a read-in numeral or arithmetic result at the upper stage.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a method for displaying memory contents in electronic devices such as calculators and cash registers.

<Prior Art> Until now, there has been a calculator (Japanese Unexamined Patent Publication No. 49-79143) that is equipped with at least two display means, displays the calculation contents on the display means as necessary or sequentially, and can check the calculation contents during the calculation. ), or a calculator (Japanese Unexamined Patent Publication No. 50-140232) has been proposed which can switchably display a set number or operation contents on one of two display sections and a different contents from an operation register or a memory register on the other.

As described above, a calculator having a two-level display function has the advantage that by retaining the memory contents, it is possible to see the memory contents while displaying the calculation results. Therefore, this kind of upper and lower display calculator has the advantage of displaying the memory contents, such as being able to perform calculations while always checking the cumulative total in the memory. The two-stage display calculator always displays the memory contents, so the process of calculation.

It has the advantage of being able to check the cumulative total in memory, but on the other hand, when memory calculations are not required or when the memory contents are unnecessary, the memory contents are always displayed, which can lead to misreading and nuisance. . for example,
If calculation information is displayed in the upper row and clock information is displayed in the lower row, there is a risk that the display may be misread in the calculation mode.

Also, in a calculator with a game function, a similar problem occurs when game-related information is displayed on one display section in the calculation mode.

<Object of the Invention> An object of the present invention is to selectively switch and control by external operation means whether the memory contents displayed on the memory display section are displayed visually or the displayed contents are erased as necessary. To provide a method for displaying memory contents in electronic devices such as calculators and cash registers.

<Example> An example of a case where a calculator (for example, a calculator with a game function) is adopted will be described below.

In FIG. 1, 1 is the main body of the calculator, 2 is installed on the main body, and displays the contents of numbers set or the contents of calculations, and the contents of memory are displayed in the lower row 2B. 3 indicates a group of operation keys.

FIG. 2 shows an example of the above-mentioned two-tier display section, in which all segments are shown. In the case of this example, there are two rows of upper and lower rows of 8-digit Japanese character segments, and the upper row 2A displays the same as a normal calculator, with M (memory L- (minus) and E (error)). The lower row 2B is the memory contents display section and has a - (minus, '') symbol. In the figure, the decimal point at the lowest digit of the memory contents display section 2B is missing, but for example, the decimal point from the hardware When the number of display segments is limited due to constraints, for example, when using a liquid crystal display device, common signals 4 trees x display signals 34
This shows that if the matrix intersection of the book is 136 segments, there is no practical problem even if this decimal point is omitted. Also GAME I.

■ is a display segment indicating the type of game), GAME-O
VER is a segment indicating the end of the game.

FIG. 3 is a system configuration block diagram of an example of the present invention. In the figure, 4 is a central processing unit (CPU), read-only memory (ROM) 5 for storing calculation algorithms,
It has a data read/write memory (RAM) 6, and is connected via an interface circuit (■/F) 7 to a key manual device 8 having a memory display selection key 8A. In the RAM 6, D is a register that stores lead-in numerical values or calculation results, E is a register for storing memory contents, and F and G are display registers, and the contents of this register are displayed as they are. buffer (DS
It is displayed on the display (DSP) 10 via the P-BF) 9. In this 5, F is used as a register for upper stage display, and G is used as a register for lower stage display.

FIG. 4 is a flowchart showing the operation when the memory display key (CM-DSP Key) is operated, and FIG. 5 is a flowchart for explaining the operation of the display unit.

First, in FIG. 4, when the memory display key is pressed, the state of a flag M provided in the RAM 6 is inverted. In other words, if it is O, it is inverted to 1, and if it is 1, it is inverted to 0.

In Figure 5, determine whether flag M is 1 or 0 (Jl)
, i, in step A2 the contents of the E register in the RAM 6 are decoded and transferred to the G register, thereby displaying the memory contents in the lower part of the display. If the content of flag M is 0, it is represented as X in the breath code C diagram displayed in step A3. ) is transferred to the G register to blank the lower part of the display. And step A4
By decoding the contents of the D register and transferring them to the F register, the lead-in numerical values and calculation results are displayed on the upper stage. Note that each bit in the F and G registers has a one-to-one correspondence with a display segment.

In this way, memory display selection key (M-DSP) 8A
By operating the memory content display stage, it is extremely easy to display or erase the memory content display stage.

<Effects> As is clear from the above explanation, according to the present invention, it is possible to confirm the contents of the memory at any time, and when unnecessary, the display of the memory contents can be erased by a simple external operation such as a key. It is possible to eliminate misunderstandings and annoyances caused by displays.

[Brief explanation of the drawing]

FIG. 1 is an external view of an example calculator that employs the memory content display method according to the present invention, FIG. 2 is a diagram showing an example of the display section of the calculator, FIG. 3 is a system configuration block diagram of the calculator, and FIG. The figure is a flowchart for explaining the operation when the memory display selection key is operated, and FIG. 5 is a flowchart for explaining the operation on the display section. 1: Calculator body, 2: Display section, 2A: Upper display section. 2B lower display section, 3: key operation section, 4: CPtJ
. 5: ROM, 6: RAM, 7: Interface. 8: Single power device, 9: Display buffer 7, 10 m display device ○ Agent Patent attorney Yoshihiko Fukushi (and 2 others) Figure 2

Claims (1)

[Claims] (11) An electronic device having at least two display sections: a numeric value/operation content table system section for displaying numeric values or operation contents, and a memory content display section for displaying the contents of memory. The memory contents display section is provided with external operation means for selectively switching and controlling whether the memory contents displayed on the display section are visually displayed or erased. A memory content display method characterized by: