JPS6154585A - Data writing system of ic card - Google Patents

Abstract

PURPOSE:To shorten the data writing time with high accuracy by using an initial writing means for card containing a microcomputer, a verifying means, a rewriting means applying the routine processing and an additional writing means. CONSTITUTION:The first writing time t0 per byte is set shorter enough than the standard writing time and also at the writing enable time. In case it is decided the data is not satisfactorily accurate with the writing time t0, this time t0 is changed to the time t1(t1>t0). The time t1 is usually larger serveral times as much as the time t0. The stability of the data written to a PROM is subject to the total writing time with the fixed current value. Therefore the writing time of (n) times is increased up to t0+(n-1)t1 even though each writing time is kept at t1. Thus the satisfactory effect is secured from a rewriting action. The additional writing is carried out for a period of time equal to m(m>1) multiples as much as the time (nX5), where (t) and (n) show the writing time and the routine frequency respectively.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to an IC card, and particularly to a built-in memory E.
This relates to the method of writing data 71F into C.

<Prior art> In recent years, Tf4 is a plastic card that is made up of a glass card incorporating a data storage memory and a one-chip microcomputer (hereinafter referred to as microcomputer) that controls the writing of data.
1 C cards are attracting attention.

The data storage memory IC of this IC card, for example F
When writing necessary data from outside the ROMIC 1, it is necessary to take a certain amount of time to input the write signal ("If you take a certain amount of time to input the write signal, you can write data with sufficient capacity according to that time. Therefore, write 1 byte of data). : The time for writing is the standard writing time for memo IJ.
f It is not determined by C, but in this standard time yl
(, t3), the entire write operation will take a long time when attempting to write multiple bytes of data at once.

For example, the standard write time for an ultraviolet erase type PRoM is about 50 m5ec, so if you want to write the entire capacity of memo 1,110, the total write time is 16I (pit; 50m5ecX2 (148 bar center)). =102.4sec64J (pit; 50m5e
cX 8192z'(t==409.6sec128
Pit: 50m5ecX16i4byte==8
The time is 19.2 seconds.

In addition, in an example of electrically erasable FROM, each byte has 2
0 m5ec % RAM can increase the writing speed to about 100 to 300 m5ec, but when such a memory IC is used, it is functionally inferior to an IC card in terms of storage data storage performance. I end up.

<Problems to be Solved by the Present Invention> 1) When writing data to It OM in the fC card, first write to one byte in a time sufficiently shorter than the standard write time, such as I Usec, It is determined by verification that it has been written accurately at a sufficient level. If not, it is determined that the
The maximum number of times you can write repeatedly is -11! , a re-write routine is provided that repeats the write-in time by changing the setting to several times the initial write time, such as 2m5ec, which is twice 1rrLsCc, until one of the conditions is met. After that, the number of times of repeated writing, and the writing time of 1t
The present invention provides an IC card data writing method that performs accurate writing at a sufficient level in a short time by performing additional writing of nXt's m1 sound, for example, four times as much.

<Means and operations for solving the problems> The present invention will be described in detail below with reference to the drawings.

Referring to FIG. 2, which is a schematic diagram of an IC card.

A one-chip microcomputer (20) is installed in a part of the card that is the size and thickness of a commonly used cash card.
, and ROM 00) for storing data. Furthermore, a plurality of external connection terminals for data communication with external terminal devices are provided.

FIG. 3 shows the functional blocks of the IC card used in the present invention [C
-, ln le. Referring to the same figure, one-chip microcontroller (
20) C. Interface (221) via the lotus wire.
, (29+, CPU (24+, RAM (2G+)
, ROM (28) It's empty. A ROM f30 for data storage is connected to an interface 4 of a one-chip microcomputer (2cIl) by a data line, an address line, and a program mode line.

Interface (exposed is for external terminal device,
It is connected to the terminal device through an external connection terminal (121).

By the program written in ROM (281),
Processing such as data writing and reading is performed between the external terminal device and the ROM (301) under the control of the CPU (301).

Next, specific operations according to the present invention will be explained with reference to FIG. 1, which is a flowchart thereof.

When writing data to ROM C30+,
First, a write operation voltage vpp is applied from the terminal device 501 to the IC card. Next, in step s1, a predetermined write address of the ROM (301) is specified through the address line.

Next, in step S2, the write time t per byte is determined when the first write is performed. Set.

Here t. must be sufficiently shorter than the standard writing time, and must be a time in which writing is expected to be possible to some extent. In this example, t. =1 msec. In step S, the settings have been made in advance.

Clear the counter data for the write count counter. This counter is incremented by 1 each time step S is passed. In the next step S, the write time t set in step S2 is determined. The first write will be performed according to the instructions.

Here, if it is not determined that the data has been written sufficiently and accurately in the first write execution, that is, in the write execution by to, the writing time is changed to tl in step So.

Here tl is t. longer (usually several times longer).

In this example, it is doubled, that is, tl 22 m5ec
And so.

Here, it is possible to increase the write time every time the number of writes increases; nb'''-, for example, by +i In other words, under a constant current value, the total writing time depends on the total writing time, so even if the writing time for each -th time remains tl, if writing is performed up to 11 times, it will increase to t, + (n-1)j. Because of this, I thought that rewriting would not be effective enough.

The step S. If it is determined that the data has been written sufficiently and accurately by the verify check in step s8, or if it is not determined in step s8 that the number of writes is equal to the maximum number of writes, additional writing is performed in step S7. .

The catch-up is to obtain data certainty.
Writing time: [, Number of routines; n, then n X
The process is performed for a time that is t multiplied by m.

(In this example, = 4) Therefore, the additional write time is 7
71XnXt However, in the present invention, this additional writing does not send 771Xn pulses of 1 hour; t, but gives time of m X n X t as one pulse. This is because sending a large number of short pulses can cause signal disturbances, and loss of effective writing time due to the time constant at the rise of each pulse, so it is more effective to perform additional writing by sending one long pulse. by.

Now, when the additional writing is completed, the total writing time: ts is the sum of the times for the initial writing, rewriting, and additional writing.

Parameters that determine each writing time, t, n, 6,
In both cases, the smaller the value of m, the shorter the writing time1, and the more stable the data is inserted, but the number of writes; ts when n is n-Q-1 is less than the standard value. Each parameter may be set so that it is shorter than the gull writing time and [S is longer than or equal to the standard writing time when n is 0 stones.

<Effects of the Invention> In this way, the data writing method for an IC card can be changed to a method in which data is written using the initial (g)-g writing means, the verifying means, the five writing means using routine processing, and the ≠ additional writing means. By doing so, compared to writing in standard time, it is possible to write in a shorter time without losing accuracy, and this produces an extremely superior effect.

[Brief explanation of drawings]

Figure 1 is a flowchart showing the writing method according to the present invention, Figure 2 is a schematic explanatory diagram of an IC card, and Figure 3 is an IC card.
An explanatory diagram of a block diagram of a card. (10)...IC card (121...External connection terminal c2G...One-chip microcomputer (22+,
12! Jl゛°゛Interface (
24)...CPU(26)...11 AM
(28+...-I'tOM(30I・
・・External a OM

Claims (1)

[Claims] 1) A data storage semiconductor memory (P-
ROM), an IC card equipped with a one-chip microcomputer that controls writing and reading of the memory, an initial writing means for writing data in a time t_0 that is sufficiently shorter than the standard writing time, and the written data. and a verification means that compares the data with the data on the terminal side and determines whether sufficient writing has been performed.
A rewriting means repeats the routine process up to e times and performs rewriting in time t_1, which is longer than the t_0, and finally, performs additional writing in a time sufficiently larger than the initial writing time t_0 and rewriting time t_1. An IC card data writing method that writes data accurately and quickly using additional writing means and.