CN102955922A - Automatic restoring circuit for groove signals of contactless card - Google Patents
Automatic restoring circuit for groove signals of contactless card Download PDFInfo
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- CN102955922A CN102955922A CN2011102407930A CN201110240793A CN102955922A CN 102955922 A CN102955922 A CN 102955922A CN 2011102407930 A CN2011102407930 A CN 2011102407930A CN 201110240793 A CN201110240793 A CN 201110240793A CN 102955922 A CN102955922 A CN 102955922A
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Abstract
The invention discloses an automatic restoring circuit for groove signals of a contactless card. The automatic restoring circuit comprises an RF (radio frequency) module, an N-bit counter, a preset value module, a comparer and a data latch, wherein the RF module is used for receiving radio frequency signals and restoring clock signals which include data information; the N-bit counter is used for counting low-level duration time of the groove signals outputted by the RF module; the preset value module is used for presetting a maximum tolerable low-level duration time value of the groove signals; the comparer is used for comparing an output value of the counter with the preset value, and outputting a marking signal when the output value is equal to the preset value; and the data latch is used for sampling the marking signal outputted by the comparer, obtaining the marking signal at the output end Q of the comparer and enabling the RF module to restore by the aid of the marking signal so as to enable the groove signals to restore to the correct high level. The groove signals can restore to the correct high level to enable subsequent communication to be proceeded normally when the groove signals are overlength.
Description
Technical field
The present invention relates to the contactless card field, particularly relate to a kind of contactless card groove signal automatic restoring circuit.
Background technology
Data Transmission system is well-known, and is widely used in the remote portable data equipment exchange message in position and concludes the business.Described portable data equipment is commonly called card, smart card or label.Equally, data Transmission system is commonly called card reader.When card enters the excitation area of card reader, the transaction beginning.Specifically, card reader (terminal) produces power signal and data-signal (information signal), and transmits this data-signal with carrier signal.The card remote power feeding is given in the detection of carrier signal and reception, and makes card can carry out its expectation function.
Can use (that is, contactless) data equipment (that is, card) of remote power feeding to carry out multiple-task, comprise antitheft, personnel or material identification and control, the record of automatic charging, money and service transacting and control etc.Contactless card is divided into again tight coupling integrated circuit card (CICC), nearly coupling integration circuit card (PICC) and thin coupling integration circuit card (VICC) three major types.For contactless card, ISO (International Organization for Standard, ISO (International Standards Organization)) and IEC (International Electrotechnical Commission, International Electrotechnical Commissio) be formed for the specialized system of global standards.Specifically, to nearly coupling integration circuit card, the ISO/IEC of international organization has defined international standard ISO/IEC14443, and this standard is defined physical characteristics, radio-frequency power and signaling interface, initialization and anti-collision and the host-host protocol of nearly coupling integration circuit card.
According to the ISO/IEC14443 consensus standard, be divided into typeA (type A) and two kinds of interface types of typeB (type B), wherein the degree of modulation of typeB only has about 10%, and typeA then is 100%.Like this, if compatible two kinds of interface types of RF (radio frequency) demodulator circuit, then when the typeA pattern, probably mislead is transferred because the signal amplitude on the antenna changes, such as field intensity sudden change, during such as many card anti-collision, the RF demodulator circuit is mistakened as do normal signal and carries out demodulation, thereby cause the subsequent communications mistake, even can't proper communication.
Summary of the invention
The technical problem to be solved in the present invention provides a kind of contactless card groove signal automatic restoring circuit, when the groove signal overlength, can make groove signal return to correct high level, so that subsequent communications can normally be carried out.
For solving the problems of the technologies described above, contactless card groove signal automatic restoring circuit of the present invention comprises:
One RF module is used for receiving radiofrequency signal and the recovered clock signal with data message;
One N digit counter is connected with described RF module, counts for the low duration of the groove signal that this RF module is exported;
One preset value module is used for the tolerable maximum low level duration value of pregroove signal;
One comparer is connected with the output terminal of described N digit counter and preset value module, is used for the output valve of more described N digit counter and the preset value of preset value module, when both are equal, and the output identification signal;
One data latches, its data input pin D is connected with the output terminal of described comparer, the marking signal that is used for the output of sampling comparer, and obtain marking signal at the output terminal Q of described data latches, and with this marking signal described RF module is resetted, make groove signal return to correct high level.
Adopt contactless card groove signal automatic restoring circuit of the present invention, the signal that receives on antenna is misread timing because changes in amplitude causes the RF module, can detect the overlength groove signal, and produce a marking signal to the RF module, the RF module is resetted, finally make groove signal return to correct high level, the assurance subsequent communications can normally be carried out.
Description of drawings
The present invention is further detailed explanation below in conjunction with accompanying drawing and embodiment:
Accompanying drawing is contactless card groove signal automatic restoring circuit one embodiment schematic diagram.
Embodiment
Shown in accompanying drawing, described contactless card groove signal automatic restoring circuit comprises: RF module 100, N digit counter 110, preset value module 120, comparer 130, data latches 140 in one embodiment.
Comparer 130 is connected with the output terminal of described N digit counter and preset value module, and the count value of N digit counter 110 outputs and the preset value of preset value module 120 are compared, if both are equal, then provides marking signal.Namely determine by the low level duration length of detecting groove signal pause whether groove signal pause is normal; If the low duration length of groove signal pause reaches preset value, then produce marking signal.
More than by specific embodiment the present invention is had been described in detail, but these are not to be construed as limiting the invention.In the situation that does not break away from the principle of the invention, those skilled in the art also can make many distortion and improvement, and these also should be considered as protection scope of the present invention.
Claims (3)
1. a contactless card groove signal automatic restoring circuit is characterized in that, comprising:
One RF module is used for receiving radiofrequency signal and the recovered clock signal with data message;
One N digit counter is connected with described RF module, counts for the low duration of the groove signal that this RF module is exported;
One preset value module is used for the tolerable maximum low level duration value of pregroove signal;
One comparer is connected with the output terminal of described N digit counter and preset value module, is used for the output valve of more described N digit counter and the preset value of preset value module, when both are equal, and the output identification signal;
One data latches, its data input pin D is connected with the output terminal of described comparer, the marking signal that is used for the output of sampling comparer, and obtain marking signal at the output terminal Q of described data latches, and with this marking signal described RF module is resetted, make groove signal return to correct high level.
2. automatic restoring circuit as claimed in claim 1, it is characterized in that: described radiofrequency signal is based on ISO/IEC14443 type A or type B interface.
3. automatic restoring circuit as claimed in claim 1 is characterized in that: be used for preset value relatively, can arrange by storer, also can directly solidify by hardware.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011102407930A CN102955922A (en) | 2011-08-22 | 2011-08-22 | Automatic restoring circuit for groove signals of contactless card |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011102407930A CN102955922A (en) | 2011-08-22 | 2011-08-22 | Automatic restoring circuit for groove signals of contactless card |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN102955922A true CN102955922A (en) | 2013-03-06 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2011102407930A Pending CN102955922A (en) | 2011-08-22 | 2011-08-22 | Automatic restoring circuit for groove signals of contactless card |
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| CN (1) | CN102955922A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104361390A (en) * | 2014-12-09 | 2015-02-18 | 上海坤锐电子科技有限公司 | SIM (Subscriber Identity Module) card and method for achieving high-frequency mobile payment full-card FDT |
| CN109787606A (en) * | 2019-01-09 | 2019-05-21 | 电子科技大学 | The row gating protection circuit of infrared focal plane array |
| CN109787605A (en) * | 2018-12-27 | 2019-05-21 | 北京安酷智芯科技有限公司 | A kind of logic circuit |
| CN110138376A (en) * | 2019-05-21 | 2019-08-16 | 电子科技大学 | A kind of bad row protection circuit applied to non-refrigerating infrared focal plane reading circuit |
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| US5233617A (en) * | 1990-04-13 | 1993-08-03 | Vlsi Technology, Inc. | Asynchronous latch circuit and register |
| US6073856A (en) * | 1997-09-05 | 2000-06-13 | Dai Nippon Printing Co., Ltd. | Noncontact IC device |
| CN101021739A (en) * | 2007-03-28 | 2007-08-22 | 威盛电子股份有限公司 | Resetting system and resetting method |
| CN101236735A (en) * | 2007-01-31 | 2008-08-06 | 恩益禧电子股份有限公司 | Liquid crystal display device, source driver, and method of driving liquid crystal display panel |
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2011
- 2011-08-22 CN CN2011102407930A patent/CN102955922A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5233617A (en) * | 1990-04-13 | 1993-08-03 | Vlsi Technology, Inc. | Asynchronous latch circuit and register |
| US6073856A (en) * | 1997-09-05 | 2000-06-13 | Dai Nippon Printing Co., Ltd. | Noncontact IC device |
| CN101236735A (en) * | 2007-01-31 | 2008-08-06 | 恩益禧电子股份有限公司 | Liquid crystal display device, source driver, and method of driving liquid crystal display panel |
| CN101021739A (en) * | 2007-03-28 | 2007-08-22 | 威盛电子股份有限公司 | Resetting system and resetting method |
Non-Patent Citations (1)
| Title |
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| 伍尚志: "RFID智能卡芯片模拟前端的设计与实现", 《中山大学硕士学位论文》, 29 October 2010 (2010-10-29) * |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104361390A (en) * | 2014-12-09 | 2015-02-18 | 上海坤锐电子科技有限公司 | SIM (Subscriber Identity Module) card and method for achieving high-frequency mobile payment full-card FDT |
| CN109787605A (en) * | 2018-12-27 | 2019-05-21 | 北京安酷智芯科技有限公司 | A kind of logic circuit |
| CN109787605B (en) * | 2018-12-27 | 2023-05-09 | 北京安酷智芯科技有限公司 | Logic circuit |
| CN109787606A (en) * | 2019-01-09 | 2019-05-21 | 电子科技大学 | The row gating protection circuit of infrared focal plane array |
| CN110138376A (en) * | 2019-05-21 | 2019-08-16 | 电子科技大学 | A kind of bad row protection circuit applied to non-refrigerating infrared focal plane reading circuit |
| CN110138376B (en) * | 2019-05-21 | 2023-02-24 | 电子科技大学 | Bad row protection circuit applied to uncooled infrared focal plane reading circuit |
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Application publication date: 20130306 |