JPH0263349A - Data communication system between read/write device and contactless memory module - Google Patents

Abstract

PURPOSE:To make the system immune to external noise and to simplify the circuit constitution by providing a margin at a contactless memory module(MM) side. CONSTITUTION:The 2nd coil 24 of an MM 23 receives a wave and the received wave is clamped at a logic circuit input by a clamp circuit 26 energized from a power supply circuit 25 to form a signal of levels '0', '1'. The output wave is counted by a counter 27 and a digital band pass filter 28 detects a terminator signal. After the terminator signal is detected, bits of the output of the counter 27 excluding the low-order 3 bits are latched by a latch 33 to obtain a margin by 8 waveforms. When the number of latched data is 64 or over, the data is regarded as a preamble, a decoder 34 is enabled, and when number of latched data is less than 64, the data is regarded as an instruction and the data is decoded by the decoder 34. Since the margin is provided from the side of the MM 23 in this way, the system is hardly susceptible to noise and since no analog filter is required in the side of the MM 23, the circuit constitution is simplified.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a data communication system in which operating power is supplied from a read/write device to a non-contact memory module in a non-contact manner and data is transmitted between the two.

[Prior Art] As a conventional data communication system of this type, there is one as shown in FIG. 5, for example.

In FIG. 5, 1 is a read/write device (hereinafter abbreviated as R/W), and R/W"l is a frequency fl.

f2. Three sine wave generators 3~ each generating f3
5, a multiplexer 6, a transmitting coil 7, a receiving coil 17, and a filter 18.

On the other hand, 2 is a non-contact memory module (hereinafter abbreviated as MM), and MM2 includes a receiving coil 8, a power supply circuit 9,
Filter 10 for frequency f1, filter 11 for frequency f2
, a filter 12 for frequency f3, a nonvolatile memory 13, a sine wave generator 14 that generates frequency f4, and an AND circuit 1
5, and a transmitting coil 16.

Here, when MM2 requires three signals, R
/W'l, three sine wave generators 3, 4°5 generate the frequency f
l, f2. f3 is generated, switched by multiplexer 6, and sent signal to MM2 by coil 7. The MM 2 receives the signal with the coil 8 , uses the power supply circuit 9 as an internal power source, recognizes the signal with the filters 10 , 11 , and 12 , and sends the signal to the nonvolatile memory unit 13 . If the signal is an output signal, the next data is written to the non-volatile memory 13, if it is a read signal, the data from the non-volatile memory 13 is read, and if the data is tt 1 IP, the sine wave generator 14 The frequency f4 generated by coil 1
6 to R/W"l.

R/Wl is received by a coil 17 and passed through a filter 18 to obtain data it 199.

[Problem to be solved by the invention] However, in such conventional data communication systems, when there is disturbance noise, it is not possible to take a margin on the MM side, so there is a problem that it is easily affected by noise. There was a point. Further, since there are filters for the number of signals on the MM side, there is a problem that the circuit configuration becomes large and the power consumption also increases.

The present invention has been made in view of these conventional problems, and it is an object of the present invention to provide a data communication system that is not affected by noise and has a simplified circuit configuration.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a data communication system that transmits data in a non-contact manner between a memory module having a nonvolatile memory and a readout device. A transmission signal having a frequency f1 and a transmission signal having a frequency f2 is transmitted via a coil, and the receiving side receives the transmission signal via the coil and converts the transmission signal to the terminator signal f1.
is detected by a detection means, the number of waves of the transmission signal f2 between the terminator signal f1 is counted, and the number of waves is made to correspond to the data to identify the data.

[Function] In the present invention, the communication signal is in the format of "preamplifier terminator" + "data according to command" + "terminator", and the frequency f1 of the "terminator" is set to a certain number of waves, for example, 2 waves, " The frequency f2 of the preamplifier is set to a fixed number of waves, for example, 64 or more, and the frequency f2 of "data corresponding to the command" is set to only the number corresponding to the command. As a result, communication data only needs to change the number of waves, so
Since instructions can be multiplexed and the number of waves is within a certain range, a noise margin can be secured. Therefore, it becomes less susceptible to disturbance noise.

Furthermore, since the filter only needs to be able to detect the frequency f1 of the "terminator", the circuit configuration on the receiving side can be miniaturized. By roughly converting the received waves into digital signals and providing a digital bandpass filter through which only the waves of frequency f1 pass, most circuits can be digitized and the circuit configuration can be further miniaturized.

[Example] Embodiments of the present invention will be described below based on the drawings.

1 to 4 are diagrams showing one embodiment of the present invention.

In FIG. 1, 21 is a transmission signal generator provided in the R/W 20, and the transmission signal generator 21 transmits transmission signals having two types of frequencies ft and f2 to the MM 23 via the first coil 22. do. As shown in Figure 2, the transmission signal consists of a preamble (f2: 64 waves or more), a terminator (fl: 2 waves) + data according to the command (f2: wave number according to the command) + terminator (fl: 2 waves). wave), and the “preamble” part of these transmitted signals is
This shows that power is applied to MM23 and that what comes next is "data".

Also, the “terminator” enables the decoder for the next “data”, and the “data” recognizes the instruction by counting the number of waves up to the last “terminator” and decoding that number, and the non-volatile It is designed to give instructions to sexual memory.

24 is a second coil, which receives the transmission signal and provides the reception signal to a power supply circuit 25 and a clamp circuit 26. The power supply circuit 25 uses the received signal from the second coil 24 as a power source for the system, and the clamp circuit 26 clamps the received signal and makes it an "OI+ or l (11U signal)."

The output of the clamp circuit 26 is input to a counter 27 and a digital band pass filter 28, respectively.
, and the digital bandpass filter 28 detects the terminator signal.

The reason for using the digital bandpass filter 28 here is that with a normal analog filter, the filter is not stable enough with one waveform, and the output cannot be adjusted to 1q, but the digital bandpass filter 28 can output even if the waveform is only a half wave. It's because you can get it. As shown in FIG. 3, the digital bandpass filter 28 includes a shift register 29 and an AND circuit 30.
31 and an OR circuit 32, the output is obtained only with half waves, and the output of the other half waves is obtained by inverting the logic of the shift register 29. In this way, by using the digital bandpass filter 28, even half waves can be detected, so the number of communication waves can be reduced, and a margin can be obtained against waveform distortion. Note that FIG. 4 shows input waves that can be detected.

When the digital bandpass filter 28 detects the terminator signal, the latch 33 latches the output of the counter 27 except for the lower three bits.

Here, a margin for eight waveforms is provided.

If the number of latched data is 64 or more, it is regarded as a preamble and the decoder 34 is enabled; if it is less than 64, it is regarded as a command and decoded by the decoder 34,
The output of the decoder 34 is input to the nonvolatile memory 35.

For example, the number of waves 16 to 23 corresponds to "1", and the number of waves 24 to 23 corresponds to "1".
31 corresponds to rOJ. Also, other commands can be assigned to other wave numbers.

If the signal input to the nonvolatile memory 35 is a read/output signal, data is written to the nonvolatile memory 35, and if it is a read signal, data is read from the nonvolatile memory 35.

36 is a multiplexer, and the multiplexer 36 selects the frequency f3.f/l generated by the oscillator 37.38 according to the "OI+" or "1" data of the nonvolatile memory 35.
and transmits data to the R/W 20 via the three third coils.

Reference numeral 40 denotes a fourth coil. The fourth coil 40 receives data, detects it with a frequency f3 filter 41 and a frequency f4 filter 42, and identifies "'O" or "1" data.

Next, the operation will be explained.

Two types of frequencies f from the transmission signal generator 21 of the R/W 20
Transmission signal 1'' preamble (f2;
64 waves or more > Pa 10' terminator (fl; 2 waves > PI
+11 data (f2; wave number according to the command) ``+''terminator (fl; 2 waves)] is output and transmitted to the MM 23 by the first coil 22.

The MM 23 receives the received wave with the second coil 24, uses the received wave as a power source with the power supply circuit 25, and clamps it to the logic circuit input with the clamp circuit 26 to produce a signal of "(049L"1").

While counting the output waves with a counter 27, a terminator signal is examined with a digital bandpass filter 28.

Once the terminator signal is detected, the latch 33 latches the output of the counter 27 except for the lower three bits. Here, a margin for eight waveforms can be obtained. If the number of latched data is 64 or more, it is regarded as a preamble, and the decoder 34 is enabled; if it is less than 64, it is regarded as a command, and the decoder 34 decodes it. and,
The output of the decoder 34 is transmitted to a non-volatile memory unit 35.

If the signal input to the non-volatile memory unit 35 is a write signal, subsequent data is stored in the non-volatile memory 35.
For write and read signals, the non-volatile memory 35
According to "QIZ1'1" of the data from
7,38 frequency f3. f4 is switched by the multiplexer 36 and sent to the R/W 20 by the third coil 39.

The R/W 20 is received by the fourth coil 40, detected by the f3 filter 41 and the f4 filter 42, and QZI "1"
Recognize data.

In this way, in this communication system, even if the waveform is affected to some extent by disturbance noise, there is a margin on the MM 23 side, so it is less susceptible to the influence of noise.

Further, since an analog filter or the like is not required on the MM23 side, the circuit configuration can be simplified and power consumption can be reduced.

Roughly speaking, since the signal is a series of frequencies, power can always be supplied from the unsampled portion.

[Effects of the Invention] As explained above, according to the present invention, since a margin is provided on the MM side, it is less susceptible to disturbance noise, and an analog filter is not required, so the circuit configuration can be simplified. can be simplified.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing an embodiment of the present invention, Fig. 2 is a waveform diagram of a transmitted signal, Fig. 3 is a groove diagram of a digital bandpass filter, and Fig. 4 is a diagram showing detectable input waves. , FIG. 5 is a block diagram showing a conventional example. In the figure, 20... R/W (read/write device), 21... Transmission signal generator, 22... First coil, 23... MM (non-contact memory module), 24...
...Second coil, 25...Power supply circuit, 26...Clamp circuit, 27...Counter, 28...Digital band pass filter, 29...Shift register, 30.31...AND circuit , 32...OR circuit, 33...latch, 34...decoder, 35...nonvolatile memory, 36...multiplexer, 37.38...oscillator, three...third coil , 40... Fourth coil, 41.42... Filter.

Claims (1)

[Claims] In a data communication method that transmits data without contact between a memory module having a nonvolatile memory and a read/write device, a transmission signal is transmitted via a coil with a terminator signal having a frequency f1 and a transmission signal having a frequency f2. On the receiving side, the transmission signal is received through a coil, the terminator signal f1 is detected by a detection means, the wave number of the transmission signal f2 between the terminator signal f1 is counted, and the number of waves is calculated. A data communication method characterized by identifying data in correspondence with the data.