JPS60231285A - Communication method with memory card - Google Patents

Abstract

PURPOSE:To change a parallel/serial conversion format every data communication and to prevent communication data from being stolen or a memory card from data leakage or alteration by sending data for fixing the parallel/serial conversion format from a memory card in every data communication of an external apparatus with the memory card. CONSTITUTION:At the data communication with the external apparatus 9, the memory 7 transmits the number of three digits using random numbers. When the number is ''622'' for instance, the transmission side replaces the bit D6 of data 10 by the bit D2 by the upper two digits of ''622'' to convert the data 10 into data ''a11'', the data ''a11'' are shifted to the right direction twice by the lower one digit of ''622'' to convert the data ''a11'' into data ''b12'' and the bits D6-D1 are transmitted serially and successively. On the other hand, the receiving side receives the bits D6-D1 successively and serially to convert the obtained bits into parallel data ''b12'', shifts the data ''b12'' to the left direction twice to convert the data ''b12'' into data ''a11'' and replaces the bit D6 by the bit D2 to obtain the data 10 as normalized data. If data are to be transmitted/received again after the end of transmission/reception, the data are transmitted from the memory card 7, so that it is difficult to find out the serial/parallel conversion format and the memory card can be prevented from illegal use.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a data communication method in a memory card.

[Prior art]

In recent years, memory cards with built-in memory and data processing semiconductor integrated circuits (hereinafter referred to as ICs) and input/output terminals for communicating with external devices have been used for the purpose of identifying individuals, groups, or individuals. be. In addition, in order to eliminate the input/output terminals of the memory card,
A data processing IC performs parallel-to-serial conversion, and then serial communication is performed with external equipment.

However, since the parallel-to-serial conversion is always performed in the same format, and furthermore, the serial communication and protocol are always the same, the conversion method and communication protocol can be easily found, and data can easily be changed intentionally. have.

〔the purpose〕

An object of the present invention is to provide a communication method in which memory contents cannot be easily changed or read.

〔overview〕

When communicating with a memory card that has a built-in device that can read, write, and process data from memory and has input/output terminals, the memory card first sends all data in the form of parallel run real conversion, and then Serial communication is performed by parallel-to-serial conversion based on the data.

〔Example〕

Embodiments of the present invention will be described with reference to the drawings. 1st
The figure is an example of a block diagram during communication between a memory card and an external device, and the memory card 7 has a built-in memory 4 and an IC 3 for reading and writing the memory 4 and data processing, and is also used for communication with an external device 9. It has input terminal 1 and output terminal 2 as an external device? It is connected by a melting cable 8.

A data bus 5, an address bus, and a memory control signal line 6 are used to read and write data to and from the memory 4 of the C5.

FIG. 2 is an example of parallel-to-7 real conversion in one embodiment of the present invention, and is based on one data tri8 bit. When the memory card 7 communicates data with the external device 9, it first transmits a six-digit random number. Assuming that an example of this three-digit number is 622, in subsequent communications, the transmitting side uses the upper two digits of 622 to transmit data 10 to bit horse and bit D as shown by arrows 20 and 21.
After exchanging t and converting to data a11, the lower 1 of 622
Arrows 22, 25, 24, 25, 26° 27.2 depending on the girder
As shown in 8.29, the data b1 is shifted to the right by 2 degrees.
2 and serially transmits from 1.16 to IJ. On the other hand, the receiving side receives 11. When received in order from 1 to 2, it is converted to parallel data b12, then softened twice to the left, converted to data a11, and then bit D
, and bit D2 k is converted to obtain data 10'ff: direct parent data. Once transmission has been completed, when data is to be transmitted and received again, a new 5-digit number is first transmitted from the memory card 7, making it difficult to steal the transmitted and received data and to detect serial-to-parallel conversion formats in external devices. As a result, misuse of the memory card can be prevented.

〔effect〕

Every time an external device performs data communication with the memory card, the parallel-to-free conversion format 't-? Since the memory card sends the data stored in the memory card, the parallel-serial rewriting format is different each time data communication is performed, and it is possible to prevent theft of communication data and leakage or falsification of data on the memory card.

[Brief explanation of the drawing]

Figure 1 is a block diagram during communication between the memory card and an external mechanism, and Figure 2 is an example of parallel-to-serial conversion in one embodiment of the present invention. 1-digit input terminal, 2-digit output terminal, 3-digit terminal C14 is memory,
5 is a data bus, 6 is an address node and memory, 5 is a data node, 6 is an address node and a memory control signal line, 7 is a memory card, 8 is a cable, 9 is an external mechanism, 1
0 is data, 11 is data a, 12U data b, 20,
21.22, 25° 24.25, 26, 27.28.2
9 is an arrow. Applicant: Suwa Seikosha Co., Ltd. Agent: Patent Attorney Tsutomu Mutsumasa Mogami

Claims (1)

[Claims] A full-data memory card that has a built-in semiconductor integrated circuit that can read, write, and process data from memory, and that can first add a parallel-to-serial conversion format in data communication with a memory card that has input/output terminals. 1. A method of communicating with a memory card, the method comprising: transmitting the data to the outside, and thereafter receiving or transmitting read/write mode instructions and data in the above format.