TWI571814B - Method for emulating card reader interface and control device using the same - Google Patents

Description

Method for simulating card reading interface and control device using same

The present invention relates to a method of simulating a card reading interface and a control device therefor, and more particularly to a control device for an action point of sale device.

With the popularity of mobile devices (such as mobile phones or tablets), mobile devices can be connected to mobile point of sale (mPOS) by physical line or wireless, and applications installed around the mobile device itself and surrounding The wireless network of the environment, the mobile device can become a mobile credit card machine, allowing users to make sign-off transactions everywhere, so that the credit card machine is not necessarily limited to being set at the counter. How to design an mPOS device is one of the topics that the industry is currently working on.

It is an object of the present invention to provide a method for simulating a card reading interface and a control device therefor, to realize an mPOS device, which has the advantage of reducing production costs.

According to a first aspect of the present invention, a method for simulating a card reading interface is provided, which is applied to a control device, the control device comprising a processing unit, a universal input and output Unit, timing unit, this method is used to simulate the universal input and output unit into a card reading interface. The method comprises the steps of: setting an interrupt request from a timing unit to an interrupt request having the highest priority in the processing unit; the processing unit notifying the timing unit of the interval at which the interrupt request is issued; and when the processing unit receives the interrupt request from the timing unit The interrupt handler is entered, wherein in the interrupt handler, the processing unit reads the input value from the general purpose input and output unit.

According to a second aspect of the present invention, a control apparatus is provided, comprising a wireless transceiver unit, a universal input/output unit, a timing unit, a memory unit, a processing unit, and a bus bar. The wireless transceiver unit is configured to wirelessly send and receive data. The memory unit is used to store a program. The processing unit is configured to execute a method for loading the general-purpose input/output unit into a card reading interface when loading the program, the method comprising the steps of: setting an interrupt request from the timing unit to have the highest priority in the processing unit The interrupt request of the right; notifying the timing unit of the interval at which the interrupt request is issued; and when receiving the interrupt request from the timing unit, entering the interrupt handler, wherein in the interrupt handler, the processing unit reads the input value from the general input/output unit . The bus bar is coupled to the wireless transceiver unit, the universal input/output unit, the timing unit, the memory unit, and the processing unit.

In order to better understand the above and other aspects of the present invention, the preferred embodiments are described below, and in conjunction with the drawings, the detailed description is as follows:

1‧‧‧Mobile point of sale device

2‧‧‧Mobile devices

3‧‧‧Server

10‧‧‧Control device

101‧‧‧Processing unit

102‧‧‧ memory unit

103‧‧‧General purpose input and output unit

104‧‧‧Time unit

105‧‧‧Wireless transceiver unit

110‧‧‧ busbar

191‧‧‧Processing IC

192‧‧‧Wireless Module IC

193‧‧‧wafer card reader IC

194‧‧‧Magnetic Strip Card Reader IC

S202‧‧‧Set the interrupt request from the timing unit to the highest priority interrupt request in the processing unit

S204‧‧‧Processing unit notifies the timing unit of the interval between interrupt requests

S206‧‧‧ When the processing unit receives an interrupt request from the timing unit, it enters the interrupt handler. In the interrupt handler, the processing unit reads the input value from the general purpose input and output unit

CLK‧‧‧ clock

GPIO‧‧‧General purpose input and output

ISR‧‧‧ interrupt handler

FIG. 1 is a schematic diagram of an example action acquiring service system.

Figure 2 is a schematic diagram of an exemplary mPOS device.

FIG. 3 is a schematic diagram of a control device according to an embodiment of the invention.

FIG. 4 is a flow chart of a method for simulating a card reading interface according to an embodiment of the invention.

FIG. 5 is a timing diagram of signals for writing an output value to a general-purpose input/output unit according to an embodiment of the invention.

FIG. 6 is a timing diagram of signals for reading an input value from a general-purpose input/output unit according to an embodiment of the invention.

FIG. 1 is a schematic diagram of an example action acquiring service system. The system includes an mPOS device 1, a mobile device 2, and a server 3. The mobile device 2 is, for example, a mobile phone or a tablet computer, and is represented by a mobile phone in the illustration. The mobile device 2 can be connected to the remote server 3 through its own wireless network (for example, WiFi or LTE), and the mobile device 2 can be Connect to the mPOS device 1 via wireless communication technology such as Bluetooth or Near Field Communication (NFC). The mPOS device 1 can, for example, read a wafer card (such as a chip of a smart card) and a magnetic stripe card (such as a magnetic stripe of a credit card). When the user swipe the card, the mPOS device 1 can transmit the read data to the mobile device 2, The mobile device 2 can be installed with an application corresponding to the action card to handle the action related to the transaction, and the mobile device 2 can further transmit the transaction data to the remote server 3 via the wireless network to complete the transaction.

Figure 2 is a schematic diagram of an exemplary mPOS device. As number 1 The mPOS device 1 in the illustrated example can read the chip card and the magnetic stripe card, and also has wireless data transmission capability. Therefore, an example mPOS device is implemented as shown in FIG. 2, and the mPOS device includes a processor product. An integrated circuit (IC) 191, a wireless module IC 192, a chip card reader IC 193, and a magnetic stripe card reader IC 194. The processor IC 191 is coupled to other integrated circuits, including a wireless module IC 192, a chip card reader IC 193, and a magnetic stripe card reader IC 194. The processor IC 191 can be a central processing unit or a microcontroller. Perform operation control on data calculation and peripheral units. The wireless module IC 192 is, for example, a Bluetooth communication module. The wafer card reader IC 193 can convert the data read from the wafer card into a signal type that the processor IC can process. Similarly, the magnetic stripe card reader IC 194 can convert the data read from the magnetic stripe card into a signal type that the processor IC 191 can process. However, in the exemplary mPOS device shown in FIG. 2, a total of four independent integrated circuit chips are required, occupying a large physical circuit area and requiring high production cost. A method implemented by a single integrated circuit and an apparatus using the same are presented below.

FIG. 3 is a schematic diagram of a control device according to an embodiment of the invention. The control device 10 includes a wireless transceiving unit 105, a general-purpose input-output unit 103, a timing unit 104, a memory unit 102, a processing unit 101, and a bus bar 110. The wireless transceiver unit 105 is configured to wirelessly transmit and receive data. The memory unit 102 is configured to store a program. The processing unit 101 is configured to execute a method for loading the general-purpose input/output unit 103 into a card reading interface when loading the program. The method includes the following steps: setting an interrupt request from the timing unit 104 as the processing unit 101. The highest priority interrupt request; the notification timing unit 104 issues an interrupt request The interrupt processing routine is entered when an interrupt request from the timing unit 104 is received, wherein the processing unit 101 reads the input value from the general-purpose input-output unit 103 in the interrupt processing routine. The bus bar 110 is coupled to the wireless transceiver unit 105, the universal input/output unit 103, the timing unit 104, the memory unit 102, and the processing unit 101. Each component is described in detail below.

The control device 10 can be disposed in the mobile point of sale device 1, the control device 10 can be a microcontroller, can be implemented by a single integrated circuit, and the control device 10 can integrate the processor IC 191 shown in FIG. The functions of the wireless module IC 192, the chip card reader IC 193, and the magnetic stripe card reader IC 194. The control unit 10 is connected to each unit by a bus 110. The processing unit 101 is, for example, a microprocessor. The processing unit 101 can be configured to execute a corresponding function by loading a program. The program can be stored in the memory unit 102, which is, for example, a memory. For example, the memory unit 102 can be a random access memory (RAM), the program can be stored in the RAM in a software manner, or the memory unit 102 can be a flash memory (Flash), and the program can be in a firmware form. Embedded in flash memory.

In this embodiment, after the program stored in the memory unit 102 is loaded via the processing unit 101, the processing unit 101 can perform a method to simulate the general-purpose input-output unit 103 as a card reading interface. The General Purpose Input/Output (GPIO) unit 103 may include, for example, a plurality of general purpose input/output pins (GPIO pins), an input data register, an output data register, and a direction register. The GPIO pin is a bidirectional pin and can be used as an input or output pin. It can be determined by the value of the direction register. When the direction register is determined as the input pin, the received value can be stored in the input data register; when the direction register is determined as the output pin, the internal circuit can write the value to be transmitted to the output data. The value stored in the register and output data register is output by the GPIO pin. In the following description, for simplification of the text description, when the GPIO pin is used as an input pin, the operation of the internal circuit to read data from the input data register is indicated as reading the input value from the general-purpose input-output unit 103; When the GPIO pin is used as an output pin, the internal circuit writes the data to the output data register, which is indicated as writing the output value to the general-purpose input/output unit 103.

Since the universal input/output unit 103 of the control device 10 can be controlled by the user to control the operation thereof, in the embodiment of the present invention, the input and output signals of the universal input/output unit 103 can be controlled by appropriately programming the program. The simulation is an operation of the card reader interface. The emulated card reading interface includes a chip card reading interface and a magnetic stripe card reading interface, the wafer card reading interface such as an ISO7816 interface, and a magnetic stripe card reading interface such as an ISO7811 interface. In an embodiment, the universal input/output unit 103 includes a plurality of GPIO pins, and some of the GPIO pins (for example, Pin 1~Pin 5) are used to simulate the ISO7816 interface, and another part of the GPIO pins (for example, Pin 6~). Pin 8) is used to simulate the ISO7811 interface. Therefore, the mPOS device 1 of the application control device 10 can have both the chip card and the card reading capability of the magnetic stripe card.

In the embodiment illustrated in FIG. 3, since the general-purpose input-output unit 103 of the control device 10 can be simulated as a card reading interface by using software or firmware control, the control device 10 shown in FIG. 3 does not need to be Crystal as shown in Figure 2 The chip card reader IC 193 and the magnetic stripe card reader IC 194 function as bridge devices and can be directly connected to the card with GPIO pins. In addition, in this embodiment, the wireless transceiver unit 105 can also be integrated into the same integrated circuit, and thus the wireless module IC 192 as shown in FIG. 2 is not required. The control device 10 can be realized in a single integrated circuit, which can save circuit area, reduce integrated circuit components that are required to be used, and effectively reduce production costs. The embodiment of Figure 2 requires four independent ICs, and the embodiment of Figure 3 requires only one IC.

In one embodiment, the wireless transceiver unit 105 is a dual mode Bluetooth transceiver, for example compatible with the Bluetooth 3.0 protocol and the Bluetooth 4.0 protocol, and can be used to connect mobile devices having a Bluetooth transmission interface. The wireless transceiver unit 105 communicates with the processing unit 101 through the bus bar 110, can be controlled by the processing unit 101, and transmits the received data to the processing unit 101. The control device 10 can be applied to an mPOS machine of a Bluetooth transmission interface.

A method of simulating the general-purpose input/output unit 103 as a card reading interface will be further described below. FIG. 4 is a flow chart of a method for simulating a card reading interface according to an embodiment of the invention, the method comprising the following steps. Step S202: The interrupt request from the timing unit is set as the interrupt request having the highest priority in the processing unit. Step S204: The processing unit notifies the timing unit of the interval time for issuing the interrupt request. Step S206: When the processing unit receives the interrupt request from the timing unit, it enters an interrupt processing program, wherein in the interrupt processing program, the processing unit reads the input value from the general-purpose input/output unit. In an embodiment, in the interrupt handler, the processing unit is further configured to write the output value to the general purpose input and output unit.

Referring to FIG. 3 and FIG. 4 simultaneously, when the general-purpose input/output unit 103 is used to simulate the card reading interface, it is indicated that the processing unit 101 is to read the value of the general-purpose input-output unit 103 at the correct time point, or the processing unit 101 At the correct point in time, a value is written to the general purpose input and output unit 103 such that the signal at the universal input and output unit 103 conforms to the operational signal of the card reader interface. Since different card reader interfaces have standard protocol specification signal timing, such as the aforementioned ISO7816 and ISO7811, when the Bluetooth transceiver is also integrated into the control device 10, since the Bluetooth transmission also has a standard agreement, it is necessary to comply with a specific signal timing specification. In order to avoid the situation that the Bluetooth connection is disconnected when the card reading related action is performed, or because the magnetic stripe card may read the wrong data during the Bluetooth transmission, the signal timing control for the universal input/output unit 103 must be sufficient. accurate. For example, the output value can be written to the general purpose input and output unit 103 at a sufficiently accurate point in time to simulate a card reading interface that conforms to the ISO7816 timing specification.

In the embodiment of the present invention, in order to accurately control the signal timing of the general-purpose input/output unit 103, the method adopted is controlled by using an Interrupt Request (IRQ) transmitted by the timing unit 104. The timing unit 104 is, for example, a hardware timer including an electronic oscillator capable of generating a clock signal of a specific frequency to accurately calculate time. In the control device 10, the processing unit 101 can receive a plurality of interrupt request sources of the peripheral devices, and the interrupt request source can be from the wafer or can be received from the external circuit of the chip. The interrupt request may correspond to an Interrupt Service Routine (ISR). When the processing unit 101 receives the interrupt request, the program state currently being executed may be temporarily stored, and the interrupt request is preferentially jumped to the interrupt request. The address of the interrupt processing program in the memory unit 102 is executed to execute the interrupt processing program. After the processing unit 101 executes the interrupt processing program, the temporary program state is retrieved, and the original program is jumped back to the memory unit 102. The address, continue to execute the original program.

In the embodiment of the present invention, the interrupt processing program executed by the processing unit 101 is that the processing unit 101 reads the input value from the general-purpose input/output unit 103, or the processing unit 101 writes the output value to the general-purpose input/output unit 103. That is, each time the interrupt request is received from the timing unit 104, the processing unit 101 performs an operation of reading or writing to the general-purpose input-output unit 103. Therefore, the processing unit 101 needs to notify the timing unit 104 how long to issue an interrupt request according to the specification corresponding to the card reading interface, so that the processing unit 101 performs a read or write operation on the general-purpose input-output unit 103 at the correct time.

As previously mentioned, the processing unit 101 can receive a plurality of interrupt request sources, including the wireless transceiver unit 105 (eg, a dual mode Bluetooth transceiver) or can issue an interrupt request related to Bluetooth transmission to the processing unit 101. In order to make the signal timing of the data read/write operation of the general-purpose input-output unit 103 accurate, the interrupt request from the timing unit 104 can be set as the interrupt request having the highest priority in the processing unit 101, and the interrupt request from the other unit can be set. For lower priority. Therefore, the interrupt request from the wireless transceiver unit 105 has a lower priority than the interrupt request from the timing unit 104. By setting the priority of different interrupt request sources, the processing unit 101 immediately prioritizes its corresponding interrupt handler and receives the read or write to the general-purpose input/output unit 103 each time it receives an interrupt request from the timing unit 104. The action is written to achieve an accurate target of the signal timing at the general purpose input and output unit 103.

The processing unit 101 executes the method of the above embodiment by loading a program, and the program can be stored in the memory unit 102. The priority order of each interrupt request source can be set in this program, including setting the interrupt request from the timing unit 104 to the interrupt request having the highest priority in the processing unit 101. In the program, it is possible to set what value to be written by the processing unit 101 to the general-purpose input-output unit 103 in the interrupt processing program corresponding to the timing unit 104, and how the processing unit 101 is to process the value read from the general-purpose input-output unit 103.

First, the case where the numerical value is read from the general-purpose input-output unit 103 will be described. FIG. 5 is a timing chart showing the signal reading the input value from the general-purpose input-output unit according to an embodiment of the present invention. In this embodiment, the magnetic stripe card is read by simulating the ISO7811 interface as an example. The control device 10 can be externally coupled with an analog circuit, for example, including an operational amplifier (OP-Amp) and an analog-to-digital converter (ADC). When the user brushes the magnetic stripe card, a small current is generated due to the principle of electromagnetic induction, the small current is amplified by the analog circuit and converted into a digital signal, and the digital input signal is received by the universal input/output unit 103, and the processing unit 101 reads or reads by the program control. It is the point in time at which this digital signal is sampled.

For example, the processing unit 101 can notify the timing unit 104 to issue an interrupt request at a fixed frequency, that is, the frequency at which the processing unit 101 desamples the general-purpose input-output unit 103. As shown in FIG. 5, CLK represents a clock signal, GPIO represents a signal on a general-purpose input/output pin, and ISR represents a time point at which each timing unit 104 issues an interrupt request, that is, the processing unit 101 enters an interrupt. The point in time at which the program was processed. The ISR can be a fixed frequency such that the processing unit 101 enters an interrupt handler at a fixed frequency, in which the processing unit 101 reads the input values from the general purpose input and output unit 103, as in the example illustrated in FIG. The processing unit 101 can sequentially read {1,1,1,1,1,1,1,1,0,0,0,0,0,0,0,0,1,1,1,0,0 , 0,0,1,...}, where 1 represents a high logic level corresponding to the input value and 0 represents a low logic level corresponding to the input value. It should be noted that, in order to make the illustration clear, the signal frequency relationship shown in FIG. 5 is only a schematic diagram, and the signal frequency used by the actual circuit may be different from the ratio shown in FIG. For example, in a circuit implementation, IFIO can issue tens or hundreds of ISRs in one signal cycle, and there can be tens or hundreds of CLK cycles between each ISR.

According to the ISO7811 interface standard, the signal on the card interface distinguishes between logic 1 or logic 0 by the signal width. For example, logic 0 corresponds to 1 time period of the signal, and logic 1 corresponds to 2 times period of the signal. Therefore, in an embodiment, when the processing unit 101 reads the input value from the general-purpose input-output unit 103, the processing unit 101 further calculates a high logic level period corresponding to the input value and a low logic level period, and the processing unit 101 respectively The number of interrupt requests received from timing unit 104. As in the example shown in Figure 5, during the initial high logic level, 8 interrupt requests are received, followed by 8 low interrupt levels, followed by 8 interrupt requests, followed by the next high logic bit. During the quasi-period, three interrupt requests are received, and during the next low logic level, four interrupt requests are received. According to these numbers, the processing unit 101 can determine that a signal of 2 times period is received first, and then received. A signal with 1 cycle, so it can be known that logic 1 is received first and then logic 0 is received. The values herein are merely illustrative. In circuit implementations, processing unit 101 may receive dozens of interrupt requests during a high logic level.

Next, the case where the value is written to the general-purpose input/output unit 103 will be described. FIG. 6 is a timing chart showing the signal output to the general-purpose input/output unit according to an embodiment of the present invention. In this embodiment, the data is transferred to the wafer card by simulating the ISO 7816 interface as an example. When the user inserts the wafer card and the control device 10 needs to transmit an instruction to the wafer card, the processing unit 101 writes the value to the general purpose input/output unit 103. Similar to the operation of reading a value, each time the processing unit 101 receives an interrupt request from the timing unit 104, the processing unit 101 executes an interrupt processing program in which the program specifies the value to be written to the general-purpose input-output unit 103. Therefore, the processing unit 101 can write the value set according to the program to the general-purpose input-output unit 103 at the correct time point (by the program notifying the timing unit 104 of the interval at which the interrupt request is issued).

Taking the ISO7816 specification as an example, a byte (byte) data consists of one start bit, eight data bits, one parity bit, and two bits. The end bits are composed of stop bits. The time occupied by each bit is an Elementary Time Unit (ETU), and one ETU is 372 clock cycles. Taking the CLK signal with a frequency of 3 MHz as an example, one ETU length is 372*(1/3MHz)=124μs. Therefore, the processing unit 101 can notify the timing unit 104 that the interval for issuing the interrupt request is 124 μs, and each time the interrupt handler is entered, the value of 1 bit is written to the general-purpose input and output unit. 103. Taking Figure 6 as an example, first write the start bit to 0, and then write the most significant bit (Most Significant Bit, MSB) of the data from the Least Significant Bit (LSB) D0 of the data. D7, write the check code again, and finally write the end bit of 2 bits to 1, that is, complete the transmission of 1 byte. The control device 10 can transmit instructions of a plurality of byte groups to the wafer card at a time, wherein each of the byte groups can be written into the output value by a plurality of interrupt requests to achieve the correct time point as shown in FIG. General purpose input and output unit 103.

As described in the fifth and sixth embodiments above, the interrupt handler only needs to read 1 bit or write 1 bit value, whether in the case of reading a value or writing a value. Therefore, the time required is very short, and the processing unit 101 can immediately jump back to the original program execution after executing the short interrupt handler. Therefore, by using the method of the analog card reading interface disclosed in the embodiment of the present invention, by controlling the timing of the read and write signals by the interrupt request, not only the advantages of the timing precision control but also the interrupt processing program can be quickly ended. A program that does not affect the processing unit's original processing.

In the embodiment illustrated in FIG. 3, a timing unit 104 is illustrated. When the control device 10 simultaneously simulates two types of card reading interfaces, for example, including an ISO7816 interface and an ISO7811 interface, in one embodiment, the two interfaces can respectively correspond to different GPIO pins, and the two interfaces can respectively correspond to the respective ones. The timing unit, for example two timers with different oscillation frequencies, respectively, is suitable for different card reading interfaces. In an embodiment, the two interfaces may also correspond to the same timing unit, and the program timing unit controls the two card reading interfaces separately. How long to send an interrupt request. In the actual operation, the mPOS device does not read the chip card and the magnetic stripe card at the same time. Therefore, the analog two interface devices in the mPOS device can use the same timing unit, and the corresponding timing control is performed by the software.

The method for simulating the card reading interface disclosed in the above embodiments of the present invention and the control device using the same can realize the card reading interface with wireless transmission capability by using a single integrated circuit. Since the card reading interface is directly simulated by the universal input/output unit of the control device, no additional switching circuit is required, which has the advantages of saving circuit area and reducing production cost. In addition, by setting the priority of the interrupt request issued by the timing unit to the highest, the signal timing of the card reading interface can be made accurate, effectively avoiding the problem of data reading errors when reading important data on the card, and can read the card. While operating, maintain wireless transmission (such as Bluetooth transmission) continuously.

In conclusion, the present invention has been disclosed in the above preferred embodiments, and is not intended to limit the present invention. A person skilled in the art can make various changes and modifications without departing from the spirit and scope of the invention. Therefore, the scope of the invention is defined by the scope of the appended claims.

S202‧‧‧Set the interrupt request from the timing unit to the highest priority interrupt request in the processing unit

S204‧‧‧Processing unit notifies the timing unit of the interval between interrupt requests

S206‧‧‧ When the processing unit receives an interrupt request from the timing unit, it enters the interrupt handler. In the interrupt handler, the processing unit reads the input value from the general purpose input and output unit

Claims (12)

A method for simulating a card reading interface is applied to a control device, the control device includes a processing unit, a universal input and output unit, and a timing unit, and the method is used to simulate the universal input/output unit as a card reading interface. The method includes: setting an interrupt request from the timing unit as an interrupt request having the highest priority in the processing unit; the processing unit notifying the timing unit of an interval time for issuing the interrupt request; and when the processing unit receives the interrupt request When the interrupt request of the timing unit is requested, an interrupt processing routine is entered, in which the processing unit reads an input value from the general-purpose input/output unit. The method of claim 1, wherein the processing unit writes an output value to the universal input/output unit in the interrupt processing routine. The method of claim 1, wherein the card reading interface is an ISO7816 interface. The method of claim 1, wherein the card reading interface is an ISO 7811 interface. The method of claim 1, wherein when the processing unit reads the input value from the universal input and output unit, the processing unit calculates a high logic level period corresponding to the input value and a low logic The number of interrupt requests received by the processing unit from the timing unit during the level. A control device comprising: a wireless transceiver unit for wirelessly transmitting and receiving data; a universal input/output unit; a timing unit; a memory unit for storing a program; and a processing unit for executing a method for loading the program, the method for Simulating the universal input/output unit into a card reading interface, the method comprising: setting an interrupt request from the timing unit as an interrupt request having the highest priority in the processing unit; notifying the timing unit to issue the interrupt request Interval time; and when receiving the interrupt request from the timing unit, entering an interrupt handler, wherein in the interrupt handler, the processing unit reads an input value from the universal input output unit; and a bus The wireless transceiver unit, the universal input/output unit, the timing unit, the memory unit, and the processing unit are coupled. The control device of claim 6, wherein in the interrupt processing program, the processing unit writes an output value to the universal input/output unit. The control device of claim 6, wherein the card reading interface is an ISO7816 interface. The control device of claim 6, wherein the card reading interface is an ISO7811 interface. The control device of claim 6, wherein the processing unit calculates when the processing unit reads the input value from the universal input/output unit A number of the interrupt requests received by the processing unit from the timing unit during a high logic level period and a low logic level period corresponding to the input value. The control device of claim 6, wherein the wireless transceiver unit is a dual mode Bluetooth transceiver, and the dual mode Bluetooth transceiver sends a Bluetooth transmission interrupt request to the processing unit. The control device of claim 6, wherein the control device is implemented in a single integrated circuit.