JPS62143164A - Electronic calculator with formula storage function - Google Patents

Abstract

PURPOSE:To prevent stored data from damage by providing counters for counting up respective storage areas for numerical data and numerical formula data. CONSTITUTION:The numerical formula data and numerical data are successively inputted and stored to execute calculation based upon the numerical formula and the calculated result data are displayed on a display part 24. When the numerical formula data and numerical data stored in a common memory 18 are increased, the count values of a formula storing address counter 20 for indicating the storage area of the common memory 18 and a work address counter 19 are counted up or down and gradually close to each other. When both the count values of the counters 20, 19 coincide with each other, a coincidence circuit 25 detects the coincidence and sends a coincidence signal indicating the overflow error of the common memory 18 to an address part 12 to temporarily stop the output of a control instruction from a ROM 13. Consequently, the stored data can be prevented from damage.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a small electronic calculator with a formula storage function.

[Prior Art and its Problems] A small electronic calculator that can input and memorize mathematical formulas using a simple program has been commercialized. In this compact electronic calculation line, in addition to a work memory for storing normal numerical values, a separate memory for storing equations is provided.

However, in the case where the work memory and the memory for formula storage are provided separately as described above, there are cases where the work memory requires a large storage capacity depending on the contents of formula processing, and the memory for formula storage requires a large storage capacity. Since there are cases where a large storage capacity is required for both memories, it is necessary to secure a large storage capacity for both memories, which is extremely wasteful.

[Object of the invention 1 This invention was made in view of the above-mentioned circumstances,
An object of the present invention is to provide a small-sized electronic calculator equipped with a formula storage function that allows efficient use of memory without wasting it.

[Summary of the Invention] This invention comprises a work memory for storing numerical data and a formula storage memory for storing mathematical formulas in one shared memory, one of which is stored from the first address position and the other from l?
? In addition to setting the address system so that each address is used sequentially starting from the address position, a counter is provided to count the storage area of each numerical data and mathematical formula data, and when the count values of these counters match, that is, the storage capacity of the shared memory is full. When numerical data and formula data are stored, this is detected and recognized as a memory overflow.
This is to prevent the destruction of previously stored data.

[Embodiments of the invention] An embodiment 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 numeric keys, function keys, and alphabet keys, this key manual section 11 includes
(represented as "rST○" in the diagram) and a recall key for calling up the set formula (in the diagram, rRC, J, table, and und are provided. These key human input signals are sent to the address section 12. This address The unit 12 sends an address designation signal to the ROM 13 in response to the key input signal from the key input unit 11.

The ROM 13 outputs a control command to the control section 14 in response to the address designation signal from the address section 12, and also sends the next address designation No. 18 to the address section 12.

The control unit 14 controls the operation register 16 and the editing buffer 1 via the address bus 15 according to the control command of the ROM 13.
An address designation signal is sent to each of the memory 17, the shared memory 18, one work address counter, and the formula storage address counter 20, and in particular, a count-up signal ○P1 is sent to the work address counter 19, and a count-up signal ○P1 is sent to the formula storage address counter 19. Countdown signal to 20○P2
Output each. The calculation register 16 holds numerical data during calculation, and is connected to the editing buffer 1 memory 11, the shared memory 18, the calculation section 22, and the display register 23 via the data bus 21. Arithmetic unit 2
2 executes calculations using numerical data stored in the calculation register 1G and formula data stored in the editing buffer memory 17, and stores the calculation result data in the calculation register 16.
send it back to The display register 23 is connected to the data bus 2
1, and outputs it to the display section 24 for display. The work address counter 19 performs a direct count operation of the address indicating the range of use as a work memory in the shared memory 18 in response to the UP signal OP1 from the υ control unit 14, and the count value of the address is also , is also sent to the matching circuit 25.

In contrast to this work address counter 19, an expression storage address counter 20 receives input from the control unit 14 such as
The down signal OP2 causes the shared memory 18 to count an address value indicating the range of use as a pull-type storage memory, and the count value of that address is counted by the match circuit 25, similar to the work address counter 19.
It will also be sent to The matching circuit 25 compares the two addresses input from the work address counter 19 and the formula storage address counter 20, and if the two count values match, the address section 12 A match signal indicating a memory overflow error is sent to the ROM 13, and output of control commands by the ROM 13 is temporarily stopped.

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

First, if you want to store the formula rA+BJ as a calculation formula, for example, in the key human power section 11, "A" r+J
Perform key operations with rBJ. These key input signals are sent to the address section 12, and when the address section 12 specifies the address of the ROM 13, a control command is output from the ROM 13 to the control section 14. The control unit 14 specifies the address of the editing buffer memory 17 in accordance with this control command, and causes the formula data rA+8J and the end code "/" to be written from the first address.

Next, in order to store the input formula data in the shared memory 18, the store key of the key manual section 11 is operated. The key input using this store key is sent to the address section 12, and when the address section 12 specifies the address of the ROM 13, the ROM 13 outputs a formula storage control command to the control section 14. In order to transfer the mathematical formula data stored in the editing buffer 7 memory 17 to the shared memory 18 in accordance with this control command, the control unit 14 sends a countdown signal ○P2 to the formula storage address counter 20, and also controls the address bus 15. An address for reading data is specified in the editing buffer memory 17 through the address control. At this time,
A count value corresponding to the final address of the shared memory 18 is set as an initial value in the formula storage address counter 20. Assuming that the storage capacity of the shared memory 18 is 256 bytes, the initial value of the formula storage address counter 20 is "F
F()-1)J. Therefore, the formula data and end code rAj r+J rBJ r/J that are successively output from the editing buffer memory 11 are calculated by the callan 1-values rFF (H)J, rFE( H) J, rFD
By (H)J, rFC(H)j, the final address rFF of the shared memory 18 is sequentially rFE(1-1) from (H)J.
J, rFD ()l)J, written to the address of rFC(H)J.

As described above, by inputting a calculation formula manually and then operating the store key, various formula data are stored in the shared memory 18, and the formula storage address counter 20 is read from the control unit 14. Force run 1 ~ down signal ○
By P2, a callan l-flIl indicating the storage range of mathematical formula data in the shared memory 18 is stored.

Next, when performing δ1p using the stored mathematical formula data, the recall key of the key manual section 11 is first operated.

As a result, the mathematical formula data written in the shared memory 18 is sequentially read out to the display register 23 and displayed on the display section 24. The user selects display section 2 by operating the recall key.
When an arbitrary formula is displayed in 4, the numerical data corresponding to the variables of the formula are substituted.

For example, when assigning a numerical value to the formula rA+Bj, the formula rA
When +BJ is displayed on the display section 24, numerical values are substituted as follows. That is, first, a numerical value corresponding to the variable rAJ is entered manually using the numerical keys of the key entry section 11, and then rAJ is entered manually using the Alphabella 1- key. Depending on this key human power, A1-''Res Department 12, RO113
The υIII unit 74 specifies an address for writing the number (direct data) into the shared memory 18 according to the count value of the work address counter 19, and then inputs the call 1 to up signal OP to the work address counter 19.
Sends 1. Here, the start address roo (H) of the shared memory 18 is stored in the work address counter 19 in advance.
J is remembered as Callan 1-field, therefore,
Numerical data corresponding to the variable "A" is written to the roo (H) J address of the shared memory 18, and then the work address counter 19 is incremented by the count-up signal OP1 from the control unit 14, and the count value is increased. ro
l(H-J.Next, use the numeric keys of the key input section 11 to enter the numerical value corresponding to the variable rBJ, and use the alphabet keys to enter rBJ.According to this key input, do the same as above. Teato L・S Department 12, RO
The control unit 14 specifies an address for writing numerical data into the shared memory 18 according to the count value of the work address counter 19 via M13, and then sends a count up signal ○P1 to the work address counter 19.
Send out. Since the count value of the work address counter 19 is rol (H)J, the shared memory 1
The numerical data corresponding to the variable "B" is written to the rol (H) J address of 8, and then the work address counter 19 is activated by the count-up signal ○P1 from the control section 14.
is counted up and becomes r02(H).

At this point, the input of numerical values to the formula is completed, so the numerical data and formula data are read out from the editing buffer memory 17, the calculation is executed in the performance section 22, and the calculation result data is stored in the calculation register 16. sent and retained. This calculation result data is further stored in the shared memory 18, and is also sent to the display register 23 and displayed on the display section 24.

By inputting mathematical formula data and numerical data one after another as described above, calculations are performed using the stored mathematical formulas, and the calculation result data is displayed on the display unit 24.

Along with this, mathematical formula data is stored in the shared memory 18,
As the numerical data increases, the counts of the formula storage address counter 20 and the work address counter 19, which indicate the storage area of the shared memory 18, are counted down and counted up, respectively, and the values gradually become closer. , when the count values of the formula storage address counter 20 and the work address counter 79 match, that is, no more formula data is stored in the shared memory 18.
When it becomes impossible to store numerical data, the coincidence circuit 25 detects this, sends a coincidence signal indicating an overflow error of the shared memory 18 to the address section 12, and temporarily stops the output of the control command by the ROM 13. let

Upon input of the above matching signal, the address for error processing is output from the address section 12, and the error processing address is outputted from the address section 12.
Y) A message such as r○VERFLOWJ is displayed.

[Effects of the Invention] As described in detail above, according to the present invention, a work memory for storing numerical data and a formula storage memory for storing formulas are configured in one shared memory, and one is connected from the first address position to the other. , and the other one is controlled to be used in order from the final address position, and a counter is provided to count the storage area of each numerical data and formula data, and when the count 1 values of these counters match, In other words, when multiple field data and formula data are stored to the full storage capacity of the shared memory, this is detected and treated as a memory overflow, preventing the destruction of the data that has already been stored, so memory is not wasted. Therefore, it is possible to provide a compact electronic calculator with a formula storage function that can be used efficiently without any hassle.

[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...
・Calculation register, 17...editing buffer memory,
18... Shared memory, 19... Address counter for work, 20... Address counter for formula storage, 21.
...Data bus, 22.. Arithmetic unit, 23.. Display register, 24.. Display section, 25.. Match circuit.

Claims (1)

[Claims] In a small electronic calculator equipped with a formula storage function, either numerical data or formula data can be stored from the first address, or
a first counter that counts the storage range of numerical data in the shared memory; a second counter that counts the storage range of numerical data in the shared memory; 1. A small-sized electronic calculator having a formula storage function, characterized in that the computer is equipped with a detection means for detecting a memory overflow in the shared memory based on the count values of the first counter and the second counter.