A dual protocol conversion circuit

Abstract

The application belongs to the technical field of protocol conversion, and particularly relates to a dual-protocol conversion circuit, which comprises: a waveform generation unit for generating a reference frequency required by a set protocol supported by a protocol analysis chip, and output ends of the waveform generation unit are respectively connected with a clock port of the protocol analysis chip and a clock port of a self-supply voltage circuit unit; the protocol analysis chip is used for connecting with an external smart card through a set protocol interface, connecting with a module unit through a UART interface and a dual-protocol control unit, and performing communication rate matching and protocol format conversion between the set protocol interface and the UART interface according to the reference frequency; and the self-supply voltage circuit unit comprises a voltage boosting circuit, which is used for boosting a second voltage to a third voltage according to the reference frequency, so as to supply power for the protocol analysis chip. Thus, the application solves the problems that a product developed based on a Cat. 1 4G module cannot communicate with a smart card, and the product has a large volume and a high cost.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of protocol conversion, and particularly relates to a dual-protocol conversion circuit. BACKGROUND

[0002] At present, most products are developed based on Cat.1 4G modules or low-cost MCU platforms. The products developed based on Cat.1 modules or low-cost MCUs do not support the ISO 7816 protocol, while the general smart card requires the product to support the ISO 7816 protocol. The Cat.1 module or low-cost MCU only provides a standard UART protocol and cannot be directly converted into the ISO 7816 protocol, thereby causing the smart card and the module to be unable to communicate.

[0003] On the other hand, since different circuits require different voltages, in order to meet the demand of multi-path power supply of the product, a DCDC circuit is often added to meet the demand. However, after the DCDC circuit is added, the cost is relatively high and the volume is relatively large.

[0004] In summary, the products developed based on Cat.1 4G modules or low-cost MCU platforms do not support the ISO 7816 protocol, thereby causing the smart card and the product developed based on the Cat.1 4G module or low-cost MCU platform to be unable to communicate. On the other hand, since the DCDC circuit needs to be added, the product has a large volume and a high cost. SUMMARY

[0005] The present application aims to provide a dual-protocol conversion circuit to solve the problem that the product developed based on the Cat.1 4G module or low-cost MCU platform and the smart card cannot communicate in the prior art and the problem that the product has a large volume and a high cost.

[0006] To solve the above technical problems, the technical solutions provided by the present application and the beneficial effects corresponding to the technical solutions are as follows:

[0007] The double protocol conversion circuit of the application comprises: a first voltage power supply, a waveform generating unit, a protocol analysis chip, a double protocol control unit and a self-supply voltage circuit unit; the first voltage power supply is used to supply power to the waveform generating unit; the waveform generating unit is used to generate a reference frequency required by a set protocol supported by the protocol analysis chip, and the output end of the waveform generating unit is connected to the clock port of the protocol analysis chip and the clock port of the self-supply voltage circuit unit respectively; the protocol analysis chip is used to connect with an external smart card through a set protocol interface, to connect with a module unit through a UART interface and the double protocol control unit, and to match the communication rate and convert the protocol format of the set protocol interface and the UART interface according to the reference frequency; the double protocol control unit is used to control the sending and receiving information between the protocol analysis chip and the module unit; the self-supply voltage circuit unit comprises a boost circuit, which is used to boost a second voltage to a third voltage by using the reference frequency; the second voltage is obtained according to the first voltage power supply, and the third voltage is used to supply power to the protocol analysis chip and / or peripheral units.

[0008] The beneficial effects of the above technical solution are: the application uses the protocol analysis chip to parse the set protocol supported by the external smart card into the UART protocol that can be recognized by the external module unit according to the reference frequency, and controls the sending and receiving information between the protocol analysis chip and the module unit through the double protocol control unit, so as to realize the communication between the external smart card and the module unit. On the other hand, the self-supply voltage circuit unit boosts the second voltage power supply by using the reference frequency, so as to supply the protocol analysis chip and the peripheral units inside the product, thereby realizing the requirements of low cost, small size and energy saving. Thus, the application solves the problems that the products developed based on the Cat.14G module or the low-cost MCU platform cannot communicate with the smart card, and the problems of large product size and high cost.

[0009] Further, in order to facilitate voltage boosting, the self-supply voltage circuit unit comprises an inverter, a boost capacitor, a freewheeling diode and a filter circuit; the clock port of the inverter is connected to the waveform generating unit, which is used to process the received reference frequency into a square wave signal, and the output end is connected to one end of the boost capacitor, the other end of the boost capacitor is connected to the second voltage input end after being connected to the freewheeling diode, and the freewheeling diode is connected to the ground through the filter circuit; a third voltage output interface is arranged between the freewheeling diode and the filter circuit.

[0010] Further, in order to improve the voltage stability, a freewheeling diode is also arranged between the boost capacitor and the second voltage input end.

[0011] Further, the filter circuit is a capacitor.

[0012] Further, the dual-protocol control unit is a triode, and two ends of the triode are connected with the input and output, one end of which is connected with the URAT interface of the protocol analysis chip and the signal input interface of the module unit, and the other end is connected with the signal output interface of the module unit.

[0013] Further, the set protocol includes the ISO 7816 protocol. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 is a connection diagram of a dual-protocol conversion circuit according to the present application. DETAILED DESCRIPTION

[0015] In order to make the objects, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the accompanying drawings and embodiments.

[0016] An embodiment of a dual-protocol conversion circuit according to the present application is as shown in

[0017] The embodiment of the dual-protocol conversion circuit according to the present application is as shown in Figure 1 The circuit includes a first voltage power supply VCC1, a waveform generation unit, a self-supply voltage circuit unit, a protocol analysis unit (protocol analysis chip) and a dual-protocol control unit. The circuit is used for enabling the product developed based on a Cat.1 4G module or a low-cost MCU platform to communicate with an external smart card. In the embodiment, the product is a product developed using a Cat.1 4G module (referred to as a module unit), and the product further includes a peripheral unit. The set protocol supported by the external smart card corresponding to the product is ISO 7816.

[0018] The first voltage power supply VCC1 is used for supplying power to the waveform generation unit, the dual-protocol control unit and the module unit. The output end of the waveform generation unit is connected with the clock port CLK of the protocol analysis unit and the clock port CLK of the self-supply voltage circuit unit, respectively. The UART interface of the protocol analysis unit is connected with the module unit through the dual-protocol control unit. The module unit is provided with a voltage output interface for outputting a second voltage, and the voltage output interface is connected to the boost circuit in the self-supply voltage circuit unit, so that the boost circuit boosts the second voltage to a third voltage according to a reference frequency, for supplying power to the protocol analysis chip and the peripheral unit.

[0019] The following will be described in detail respectively.

[0020] The waveform generating unit is used to generate a reference frequency, and then the reference frequency is transmitted to the protocol analysis unit for double protocol conversion, and the other way to the self-voltage supply circuit unit, which is amplified by the self-voltage supply circuit unit and then output to the peripheral unit and the protocol analysis unit. The waveform generating unit is composed of Y2 crystal oscillator, C86, C87 capacitor, U1 inverter device, wherein Y2 crystal oscillator, C86, C87 capacitor constitute an oscillation circuit. The waveform generating unit generates the required reference frequency of ISO7816 by the crystal oscillator, capacitor oscillation and then shaping by the inverter, and provides the reference frequency for the protocol analysis unit.

[0021] The self-voltage supply circuit is composed of inverter U3, freewheeling diode D01, freewheeling diode D02, boost capacitor C33, filter capacitor C32 and filter capacitor C35 devices. The reference frequency provided by the waveform generating unit is shaped by the inverter U3, and then becomes a square wave signal, and then the square wave signal is used to charge the boost capacitor C33, and then the second voltage supply VCC2 is connected to the boost capacitor after passing through the freewheeling diode D01, in order to charge the boost capacitor, and then through the freewheeling diode D02, and then through the filter circuit to ground. The filter circuit includes filter capacitor C32 and filter capacitor C35 connected in parallel. Among them, the third voltage output interface is arranged between the freewheeling diode D02 and the filter circuit, which is used to provide the required voltage VCC3(third voltage) for the peripheral unit and the protocol analysis unit. The second voltage supply VCC2 is the voltage output from the module unit, and in this embodiment, VCC2=3.8V, VCC3=5V. The protocol analysis unit is composed of resistance R91, resistance R92 and protocol analysis chip U2, and the protocol analysis chip U2 supports ISO7816 protocol. The waveform generating unit reference waveform connects the protocol analysis chip U2, and the RST interface and U1RXD interface of the protocol analysis chip U2 are connected to the RST interface and U1RXD interface in the module unit. The protocol analysis chip is used to connect with the external smart card through the ISO7816 interface, and is used to connect with the module unit through the UART interface and the double protocol control unit, and according to the reference frequency, the ISO7816 interface and the UART interface are matched in communication rate and the protocol format is converted, and the output signal is fed back to the module unit through the UART type interface U1RXD for analysis.

[0022] The dual protocol control unit includes a triode, the C pole of which is connected to U1_RXD, the E pole is connected to U1_TXD, and the B pole is connected to VCC1, wherein U1_TXD and U1_RXD are output by the module unit, two signal levels are a receiving and a transmitting signal, and the triode is formed by a receiving and transmitting conversion. U1_RXD is connected to the protocol analysis unit and the dual protocol control unit, and according to the data analyzed by the protocol analysis unit, the data is sent to the module unit after being converted by the triode. Q13, the resistance R52 and the resistance R54 form a URAT type interface, and U1_TXD and U1_RXD are respectively connected to the 2nd pin (E pole) and the 3rd pin (C pole) of the triode Q13, and the switching between the sending end and the receiving end is realized by the triode Q13 during data interaction.

[0023] According to the reference frequency, the ISO 7816 interface and the UART interface are matched in communication rate and the protocol format is converted, the ISO 7816 protocol data of the external smart card is converted into the UART data recognized by the module unit, and the dual protocol control unit controls the receiving and transmitting information between the module unit and the protocol analysis unit. On the other hand, the self-voltage circuit unit boosts the low voltage output from the module unit to the high voltage required by the protocol analysis unit according to the reference frequency. The specific working process is as follows:

[0024] When the protocol analysis circuit works, the waveform generator provides the reference frequency for the protocol analysis unit, the protocol analysis unit takes the received reference frequency (CLK) signal as the internal reference frequency of the chip, the chip supports the ISO 7816 protocol, the chip reads the reference frequency, performs superposition processing on the 7816 protocol, and sends the superimposed signal to the module unit and the dual protocol control unit through U1_RXD. The module unit has a UART serial port (U1_TXD and U1_RXD), and the dual protocol control unit reads the U1_RXD signal of the protocol analysis unit through the switching conversion of the triode. For example, when the module unit reads the 7816 protocol data, the U1_TXD of the module unit is set to low level, the Q13 is turned on, the U1_RXD signal is changed from high level to low level, if the U1_TXD is set to high level, the Q13 is cut off, and the U1_RXD is high level, and so on.

[0025] The specific working process of the self-voltage circuit unit is as follows: the self-voltage circuit unit multiplexes the output frequency of the waveform generation unit, the frequency is amplified by U3 and output PWM1, in normal working state, VCC2 charges C33 through D01, C33 is charged to VCC2, at the same time, PWM1 also charges C33 (the polarity is opposite to that of VCC2), the voltages are superimposed to increase the voltage, and the increased voltage is output to the VCC3 required by the external unit and the protocol analysis unit through the unidirectional conduction of D02 and the filtering of C32.

[0026] The application adopts a protocol analysis chip to parse the ISO 7816 protocol supported by an external smart card according to a reference frequency into a UART protocol recognizable by a module unit, and controls the transmission and reception of information between the protocol analysis chip and the module unit through a dual-protocol control unit, so as to realize the communication between the external smart card and the module unit. On the other hand, a self-supply voltage circuit unit uses the reference frequency to boost a second voltage power supply for the protocol analysis chip and peripheral units inside the product, so as to realize the requirements of low cost, small size and energy saving. Thus, the application solves the problems that the products developed based on a Cat.14G module or a low-cost MCU platform cannot communicate with a smart card, and the products have large size and high cost.

Claims

1. A dual-protocol conversion circuit, characterized in that: The circuit includes: a first voltage power supply, a waveform generating unit, a protocol parsing chip, a dual-protocol control unit and a self-sufficient voltage circuit unit; the first voltage power supply is used to supply power to the waveform generating unit; the waveform generating unit is used to generate a reference frequency required for a set protocol supported by the protocol parsing chip, and the output end of the waveform generating unit is respectively connected to a clock port of the protocol parsing chip and a clock port of the self-sufficient voltage circuit unit; the protocol parsing chip is used to connect to an external smart card through a set protocol interface, and to connect to a module unit through a UART interface and a dual-protocol control unit, and to match the communication rate and convert the protocol format between the set protocol interface and the UART interface according to the reference frequency; the dual-protocol control unit is used to control the transmission and reception of information between the protocol parsing chip and the module unit; the self-sufficient voltage circuit unit includes a boost circuit, which is used to use the reference frequency to boost the second voltage to a third voltage; the second voltage is obtained according to the first voltage power supply, and the third voltage is used to supply power to the protocol parsing chip and / or to the peripheral unit.

2. The dual-protocol conversion circuit according to claim 1, wherein: The self-sufficient voltage circuit unit includes an inverter, a boost capacitor, a freewheeling diode and a filter circuit; the inverter clock port is connected to the waveform sounding unit, which is used to process the received reference frequency into a square wave signal, the output end is connected to one end of the boost capacitor, the other end of the boost capacitor is connected to the second voltage input end and then to the freewheeling diode, and the freewheeling diode is grounded through the filter circuit; a third voltage output interface is provided between the freewheeling diode and the filter circuit.

3. The dual-protocol conversion circuit according to claim 2, wherein: A freewheeling diode is also provided between the boost capacitor and the second voltage input terminal.

4. The dual-protocol conversion circuit according to claim 2, wherein: The filter circuit is a capacitor.

5. The dual-protocol conversion circuit according to claim 1, wherein: The dual-protocol control unit is a triode with input and output ends. One end is used to connect the URAT interface of the protocol analysis chip and the signal input interface of the module unit, and the other end is used to connect the signal output interface of the module unit.

6. The dual-protocol conversion circuit according to any one of claims 1 to 5, characterized in that: The setting protocol includes the ISO7816 protocol.

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