JPS62143165A - Electronic calculator with formula storage function - Google Patents

Abstract

PURPOSE:To completely display numerical formula data by providing a display specifying means, a mode state deciding means and a display selecting means. CONSTITUTION:A control part 14 sets up an editing mode signal to be inputted a set terminal S of a latch part 19 and a display instruction signal to be inputted to an AND circuit 20 to '0' and '1' respectively through an address part 12 and a ROM 13. Since no signal is inputted to both the set terminal S and reset terminal R of the latch part 19, the latch part 19 holds a state outputting a signal '0' from a terminal Q and a multiplexer 24 selects input data from an input terminal on the B side. When the control part 14 specifies an address to read out numerical formula data stored in the common memory 18, the read numerical formula data are sent to a display register 21 through a multiplexer 24 as display data and displayed on a display part 25. Consequently, the numerical formula data can be completely displayed on the display part 25.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention j] This invention relates to a small electronic calculator with formula storage capability.

[Prior art and its problems] l! Small-sized electronic calculators have been commercialized that can be used to substitute and store mathematical formulas using easy-to-use programs. In this type of small electronic calculator, the formula memory is used in either the edit mode to edit the formula stored in the formula memory or the display mode to simply display the stored formula data on the display. The formula data stored in the edit buffer memory is once stored in the edit buffer memory, and the formula data stored in the edit buffer memory is successively displayed on the display section.

However, the editing buffer memory is usually configured with a small memory size. Therefore, if the formula data read from the formula memory is larger than the storage capacity of the edit buffer memory, the edit buffer memory cannot store all of it even in display mode, so the display section Only a portion of the formula data read from the formula memory will be displayed.

[Object of the invention] This invention was made in view of the above-mentioned circumstances.
To provide a small electronic calculator equipped with a formula memory performance capable of completely displaying the formula data on a display section without missing even if the amount of stored formula data exceeds the storage capacity of an editing bath sofa. The purpose is to

[Key Points of the Invention] In the present invention, in the display mode, the formula data read from the memory is directly sent to the display register without going through the editing buffer memory, and is displayed on the display section. be.

[Embodiments of the invention] A practical example of the present invention will be described below with reference to the drawings.

First, the circuit configuration will be explained with reference to FIG.

In the figure, 11 is a key human power section. In addition to numerical keys, function keys, and alphabet keys, this key manual section 11 includes a "mathematical formula" key, a store key (represented as rsTOJ in the figure) for storing and setting formulas, and a recall key (represented as rsTOJ in the figure) for recalling stored formulas (in the figure). (expressed as rRcLJ)
is provided. When these keys of the key manual section 11 are operated, the key input signal is sent to the address section 12. The address unit 12 sends an address designation signal to the ROM 13 in response to a key input signal from the key input unit 11.

The ROM 13 outputs the 1iIIIiII instruction to the control unit 14 in response to the address designation signal from the address unit 12, and also sends the next address designation signal to the address unit 12.

The control unit 14 controls, via the address bus 15, a calculation register 16 that stores numerical data at the time of calculation, an editing buffer memory 17 that stores editing data for storing formulas, and a formula data according to the control command of the RO'M 13. At the same time, an address designation signal is sent to the shared memory 18 that stores numerical data, and an expression display mode signal is sent to the reset terminal R of the latch section 19, and an i is sent to the set terminal S of the latch section 19.
It outputs a collection mode signal, a display command to the AND circuit 20, and a write signal to the display register 21. The calculation register 16 is connected to the editing buffer 7 memory 17, the shared memory 18, and the calculation unit 23 via the data bus 22.
connected to. The calculation unit 23 executes calculations using the numerical data stored in the calculation register 1G and the edited data stored in the editing buffer memory 17, and sends the calculation result data back to the calculation register 16. The latch part 19
sends an output signal from the Q terminal to the AND circuit 20 and multiplexer 24 in response to inputs from the control section 14 to the set terminal S and reset terminal R. The editing buffer 7 memory 17 stores the output signal of the AND circuit 20 as wr.
It holds the data sent via the data bus 22 as the ite signal, and sends the held data to the forward input terminal of the multiplexer 24 as display data. Further, the mathematical formula data and numerical data stored in the shared memory 18 are also displayed at B of the multiplexer 24.
Sent to the I11 input terminal. The multiplexer 24 uses the signal from the Q terminal of the latch unit 19 as a select signal A/B, selects display data sent from the editing buffer memory 11 or the shared memory 18, and outputs it to the display register 21. . Then, the display register 21 holds the display data selected and output by the multiplexer 24 in accordance with the write signal from the control section 14, and displays it on the display section 25.

Next, the operation of the above embodiment will be explained.

First, we will show the operation in edit mode. When keys for substitution of mathematical data or a2 value data such as numeric keys, alphabet keys, and four arithmetic operation keys among the function keys of the key input unit 11 are operated, these key input signals are sent to the address unit 12, and the address Section 12 responded to this by RO.
Specify the address of M13. The ROM 13 reads out data corresponding to a key operated by the manual key section 11 according to the address designation from the address section 12 and sends it to the control section 14 . Here, the control section 14 specifies an address to write data into the editing buffer memory 17 according to the input from the ROM 13, and also sends an editing mode signal to the set terminal S of the latch section 19 and w to the display register 21.
The r i te signal is set to "1'°. As a result, the output signal from the Q terminal of the latch section 19 becomes "1" and is sent to the AND circuit 20 and the multiplexer 24. The multiplexer 24 receives the signal from the latch section 19. The input terminal of Ag1ll is selected by the select signal, and as a result, the data held in the editing buffer memory 17 is selected and output to the display register 21.The display register 21 then selects the input terminal of Ag1ll. multiplexer 2
The data in the editing buffer memory 17 selected in step 4 is held according to the wr r te signal from the control section 14 and displayed on the display section 25 .

Here, when the recall key of the key human power section 11 is operated to display the mathematical formula data stored in the shared memory 18,
Through the key input, the control section 14 sends the edit mode signal to the set terminal S of the latch section 19 to IIQII and the display command signal to the AND circuit 20 to IPA through the address section 12.80M13. In the latch section 19, since no signal is input to either the set terminal S or the reset terminal R, the previous state, that is, the state in which the signal "1P" is output from the Q terminal is maintained. The circuit 20 is.

Both inputs from the control section 14 and one latch section are '1'.

Therefore, wr r to the editing buffer memory 17
The te multiplied signal output is assumed to be 1°. In the editing buffer 1 memory 17, in response to the wr i te multiplication signal from the AND circuit 20, the formula data stored in the shared memory 18 is written in place of the editing data held up until then, and this is sent to the multiplexer as display data. Output to 24.

This multiplexer 24 is connected to 09' of one of the latch sections.
Since the signal from the M child is ``1'', the input terminal on the A side is selected, and as a result, the display data in the editing buffer memory 17 is sent to the display register 21 via the multiplexer 24. It will be done.

Then, the display register 21 holds the sent display data and displays it on the display section 25.

Next, the operation in display mode will be explained. Key Human Resources Department 11's ``
``a expression'' key, ``='' key among function keys, etc.
When a key designating a process for a mathematical formula is operated, the control unit 14 specifies the address of the editing buffer memory 17 via the address unit 12 and ROM 13 using the key manually. As a result, the data held in the editing buffer memory 17 is sent to the sieve unit 23, where the expansion of the mathematical formula and calculations are executed, and the resulting data is written into the shared memory 18.

The control section 14 now sets the expression display mode signal to the reset terminal R of the latch section 19 to 1'. Accordingly, the output signal from the Q terminal of the latch section 19 becomes II OII,
The multiplexer 24 selects the display data from the shared memory 18 that is input to the B sub-input terminal. As a result, the data written in the shared memory 18 as a result of the above processing is read out, sent to the display register 21 via the multiplexer 24, and displayed on the display section 25.

Here, when the recall key of the key human power section 11 is operated to display the mathematical formula data stored in the shared memory 18,
Through the key input, the control section 14 via the address section 12 and ROM 13 sets the edit mode signal to the set terminal S of the latch section 19 to "o" and sets the display command signal to the AND circuit 20 to "1". In the latch unit 19, since no signal is input to either the set terminal S or the reset terminal R, the latch unit 19 maintains the previous state, that is, the state in which the signal P0° from the Q terminal is output. therefore,
The multiplexer 24 comes to select the input data from the B-side input terminal as in the above state. Therefore, when the control unit 14 specifies an address in order to read the mathematical formula data stored in the shared memory 18, the read mathematical formula data is sent as display data to the display register 21 via the multiplexer 24, and is displayed. section 25.

C Effects of the Invention] As detailed above, according to the present invention, in the display mode, the stored mathematical formula data is directly sent to the display register without going through the editing buffer memory, and is displayed on the display section. , a small electronic calculator equipped with a formula storage number screen that can display the formula data completely on the display without missing even if the amount of stored formula data exceeds the storage capacity of the editing buffer. can be provided.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the circuit configuration of an embodiment of the present invention. 11...Key personnel department, 12...Address department, 13.
ROM, 14... Control unit, 15... Address bus, 16... Arithmetic register, 17... Editing buffer memory, 18... Shared memory, 19... Latch unit, 21 ...Display register, 22...Data bus, 23...Arithmetic unit, 24...Multiplexer, 25
...Display section.

Claims (1)

[Claims] A small electronic calculator equipped with a formula storage function capable of storing formula data, comprising a display specifying means for specifying display of the stored formula data, a determining means for determining a mode state, and a display mode determined by the determining means. A small electronic device having a formula storage function, characterized in that the display selection means selects the formula data read out according to the display specifying means and sends it to the display memory and displays it on the display section when the formula data is read out according to the display specifying means. Formula calculator.