KR20210014486A - System and method for transmitting digital signal in a vehicle - Google Patents

Abstract

The present invention relates a system for transmitting a digital signal in a vehicle to transmit and receive a digital signal optimized to a communication environment and a method thereof. According to the present invention, the system comprises: a transmission device; a reception device; and first and second transmission lines connecting the transmission device and the reception device. The receiving device receives a first digital signal including training data from the transmitting device through the first transmission line, performs an error check on the training data to generate first error check data, performs an error check on a signal level of the first digital signal to generate second error check data, and transmits a second digital signal, which includes third error check data acquired by performing a logical operation on the first error check data and the second error check data, to the transmission device through the second transmission line. The receiving device upwardly controls the signal level of the first digital signal based on the received third error check data.

Description

A digital signal transmission system in a vehicle and its method {SYSTEM AND METHOD FOR TRANSMITTING DIGITAL SIGNAL IN A VEHICLE}

The present invention relates to a digital signal transmission system in a vehicle and a method thereof, and to a technology for adaptively controlling a signal level of a digital signal transmitted from a transmitter in response to a change in a one-way communication environment.

Recent vehicles are equipped with various electronic devices, and for data communication between these electronic devices, a one-way digital signal transmission system may be used as an example.

A conventional one-way digital signal transmission system is composed of a transmitting unit and a receiving end. The transmitting end transmits a digital signal to the receiving end, and the digital signal transmitted from the transmitting end is defaulted to an initially set signal level. The signal level setting of the digital signal is defaulted by various hardware configurations, for example, amplifiers, resistors, or internal resistors provided in the transmitter.

However, it is common to set the signal level of the digital signal transmitted to the receiving end to a high signal level (output strength or signal amplitude) in consideration of an unfavorable communication environment.

As described above, in the conventional one-way digital signal transmission system, the digital signal is defaulted to a high signal level, and thus low power driving and EMI (ElectroMagnetic Interference)/EMC (ElectroMagnetic Compatibility) are disadvantageous.

Accordingly, an object of the present invention is to provide a digital signal transmission system and method in a vehicle designed to transmit and receive digital signals optimized for a communication environment.

The above-described objects and other objects, advantages, and features of the present invention, and methods of achieving them will become apparent with reference to the embodiments described below in detail together with the accompanying drawings.

A digital signal transmission system according to an aspect of the present invention includes: a transmission device; Receiving device; And first and second transmission lines connecting the transmitting device and the receiving device, wherein the receiving device receives a first digital signal including training data from the transmitting device through the first transmission line, and , Performing an error check on the training data to generate first error check data, performing an error check on a signal level of the first digital signal, generating second error check data, and checking the first error A second digital signal including third error check data obtained by logically calculating data and the second error check data is transmitted to the transmission device through the second transmission line, and the transmission device includes the received third error The signal level of the first digital signal is controlled upward based on the check data.

A digital transmission system according to another aspect of the present invention includes a transmission device; Receiving device; And first and second transmission lines connecting the transmitting device and the receiving device, wherein the receiving device receives a first digital signal including training data from the transmitting device through the first transmission line, and , Performing an error check on the training data to generate first error check data, performing an error check on a signal level of the first digital signal, generating second error check data, and checking the first error A second digital signal including data and the second error check data is transmitted to the transmission device through the second transmission line, and the transmission device includes the first and second error check data transmitted from the reception device. The signal level of the first digital signal is controlled upward by using.

In another aspect of the present invention, a digital transmission method includes the steps of: operating in a training mode by a transmitting device and a receiving device according to power on; Transmitting, by the transmitting device, a first digital signal including training data to the receiving device through a first transmission line; The receiving device receives the first digital signal, performs an error check on the training data to generate first error check data, and performs an error check on the signal level of the first digital signal to perform a second Generating error check data, and transmitting a second digital signal including the first and second error check data to the transmission device through the second transmission line; And controlling, by the transmitting device, a signal level of the first digital signal upward using the first and second error check data included in the received second digital signal.

According to the present invention, a receiving end performs an error check on training data included in a digital signal received from a transmitting end and an error check on the amplitude level of the digital signal, and the error check results are determined. By feeding back to the transmitter and controlling the signal level of the digital signal according to the error check results at the transmitter, the transmitter and the receiver can communicate with a digital signal having a signal level adaptively optimized for a communication environment.

As described above, by controlling the signal level of the digital signal according to the communication environment, it is possible not only to efficiently design for low power and to reduce EMI, but also to guarantee the integrity of the digital signal even in a communication environment under adverse conditions.

1 is a block diagram of a digital signal transmission system in a vehicle according to an embodiment of the present invention.
2 is a block diagram of a digital signal transmission system according to another embodiment of the present invention.
3 is a flowchart illustrating a method of adaptively controlling a signal level of a digital signal transmitted from a transmitting device to a receiving device according to an embodiment of the present invention.
4 and 5 are diagrams showing various system environments to which the present invention can be applied.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The embodiments of the present invention are provided to more completely describe the present invention to those of ordinary skill in the art, and the following examples may be modified in various other forms, and the scope of the present invention is as follows. It is not limited to the examples. Rather, these embodiments are provided to make the present disclosure more faithful and complete, and to completely convey the spirit of the present invention to those skilled in the art. In addition, each component in the following drawings is exaggerated for convenience and clarity of description, and the same reference numerals refer to the same elements in the drawings. As used herein, the term “and/or” includes any and all combinations of one or more of the corresponding listed items.

The terms used in this specification are used to describe specific embodiments, and are not intended to limit the present invention.

As used herein, the singular form may include the plural form unless the context clearly indicates another case. Further, as used herein, "comprise" and/or "comprising" specifies the presence of the mentioned shapes, numbers, steps, actions, members, elements and/or groups thereof. And does not exclude the presence or addition of one or more other shapes, numbers, actions, members, elements, and/or groups.

1 is a block diagram of a digital signal transmission system according to an embodiment of the present invention, and FIG. 2 is a block diagram of a digital signal transmission system according to another embodiment of the present invention.

1 and 2, a digital signal transmission system 300 according to an embodiment of the present invention is provided in a vehicle.

The digital signal transmission system 300 according to an embodiment of the present invention performs an error check of training data included in a digital signal received by a receiving end and an error check of the amplitude level of the digital signal. Then, the error check results are fed back to the transmitter, and the signal level of the digital signal is controlled by using the fed back error check results from the transmitter.

In the embodiment of the present invention, a digital signal is assumed to be a differential signal, but the description is not limited thereto. For those skilled in the art, one-way wired communication system for transmitting all kinds of digital signals It will be fully understood from the following description that can be applied to.

The digital signal transmission system 300 according to an embodiment of the present invention includes a transmission device 100 and a reception device 200.

In this embodiment, the transmitting device 100 and the receiving device 200 perform communication according to a wired communication method. To this end, the transmitting device 100 and the receiving device 200 are connected by a first transmission line 150 and a second transmission line 160.

The first transmission line 150 serves to transmit the differential signal generated by the transmission device 100 to the reception device 200. In this case, the differential signal includes a first differential signal representing the training data generated by the transmission device 100 as a first logic state and a second differential signal representing the training data as a second logic state in which the first logic state is inverted. Is a digital signal.

The first transmission line 150 (152 and 154) includes a 1-1 transmission line 152 transmitting the first differential signal and a 1-2 transmission line 154 transmitting the second differential signal. . As will be described in detail below, the training data may be data used to perform an error check in the receiving device 200.

The second transmission line serves to transmit a TTL (Transistor-Transistor Logic) signal from the reception device 200 to the transmission device, and may be referred to as a TTL transmission line.

The TTL signal is a first TTL signal representing a logical state of error check data obtained by performing an error check on the training data in the receiving device 200 and the differential signal configured to include training data in the receiving device 200. And a second TTL signal indicating a logic state of error check data obtained by performing an error check on a signal level.

Alternatively, the TTL signal is an AND operation based on the logic state of error check data obtained by performing an error check on the training data and the logic state of error check data obtained by performing an error check on the differential signal. It may be a 3 TTL signal.

When the TTL signal includes the first and second TTL signals, as shown in FIG. 2, two second transmission lines for transmitting a TTL (Transistor-Transistor Logic) signal from the receiving device 200 to the transmitting device are It may be desirable to apply to a system consisting of lines 172 and 174.

When the TTL signal is composed of one third TTL signal, as shown in FIG. 1, the second transmission line for transmitting the TTL (Transistor-Transistor Logic) signal from the receiving device 200 to the transmitting device is divided into two lines. It may be desirable to apply it to a system consisting of (172, 174).

Hereinafter, the transmission device 100 will be first described in detail.

The transmission device 100 includes a memory 110, a processing unit 120, a transceiver 130, and a counting unit 140.

Memory(110)

The memory 110 is a nonvolatile storage medium and stores training data.

The training data is data promised between the transmitting device 100 and the receiving device 200 and may be used for the purpose of performing an error check in the receiving device 200. The training data may be configured to include a plurality of bits representing a binary value such as '101010101010'.

The memory 110 outputs the training data to the processing unit 110 at the request of the processing unit 120.

In addition, the memory 110 may further store a table for the processing unit 120 to adjust the upward width of the signal level of the differential signal according to the error check result received from the reception device 200.

The table stored in the memory 110 may be represented, for example, as in Table 1 or Table 2 below.

Error check result Output level
Upward width Error check result for training data Error check result for differential signal L L L/L error +25mA increase L H L/H error +10mA increase H L H/L error +5mA increase H H H/H Normal Maintains the initially set output level or maintains the previously raised output level

In Table 1, L (Low) represents error occurrence (abnormal), and H (High) represents normal. Table 1 shows the result of the processing unit 120 checking the error on the training data from the receiving device 200 and the error checking result on the signal level (signal strength or amplitude level) of a differential signal including the training data. In the case of receiving all of the signals individually, it can be used for adjusting the upward width of the signal level of the differential signal.

The processing unit 120 determines an upward width for the output level of the transmitters 132 and Tx by referring to the table shown in Table 1, and inputs a signal level control value corresponding to the determined upward width to the transmitter 132. Then, the transmitter 132 increases the signal level of the differential signal by changing the gain value or the variable resistance value of the internally configured differential amplifier according to the input signal level control value.

One integrated error check result Output level Initially set differential signal signal level 40mA Step 1 50mA (+10 mA) Step 2 60mA (+10 mA) Step 3 70 mA (+10 mA) normal Maintain initial set output level or
Keep the previous higher output level

Table 2 shows that the processor 120 does not receive both the error check result for the training data and the error check result for the signal level of the digital signal from the receiving device 200, but at least one of the two error check results. When one integrated error check result indicating that the error check result is abnormal is received, it may be used for adjusting the upward width of the signal level of the differential signal.

When the signal level of the initially set differential signal is 40 mA, the processing unit 120 receives one integrated error check result indicating the occurrence of an error from the receiving device 200, and the error check result indicates the occurrence of an error. As shown in Fig. 2, the signal level of the initially set digital signal is controlled upward with a fixed upward width of (eg, 10 mA), and the signal level of the digital signal is controlled step by step with a fixed upward width when an additional error occurs.

Processing unit 120

The processing unit 120 basically controls and manages the overall operation of the memory 110, the transceiver 130, and the counting unit 140, and includes one or more Application Specific Integrated Circuits (ASICs), Digital Signal Processors (DSPs). ), DSPDs (Digital Signal Processing Devices), PLDs (Programmable Logic Devices), FPGAs (Field Programmable Gate Arrays), general processors, controllers, microcontrollers, microprocessors, etc.

When the transmitting device is powered on, the processing unit 120 operates in a training mode. The training mode may mean an operation mode performed prior to an operation mode in which the transmission device 100 transmits actual data to the reception device 200.

In the training mode, the processing unit 120 controls the components 120, 130, and 140 to initialize all set values set before power-on to the transmitting device 100.

The processing unit 110 reads out training data stored in the memory 130 in the training mode, and transmits the read training data to the receiving device 200 through the transceiver 130. Send.

In an embodiment, the processing unit 120 receives an error check result for the training data and an error check result for a signal level of a differential signal including the training data from the receiving device 200 through the transceiver 130. .

The processing unit 120 uses all of the two error check results to adjust the signal level (amplitude level or signal strength) of the differential signal to be transmitted to the reception device 200 in the operation mode after the training mode. The output level of the transmitters 132 and Tx is controlled upward.

The upward width of the output level may be determined by the upward width adjustment table shown in Table 1 above. For example, if both the error check result for the training data and the error check result for the signal level of the differential signal indicate an error (L/L), the processing unit 120 determines the initial set signal level of the differential signal. Control upward by the first upward width (eg, 25mA).

When the error check result for the training data indicates an error (or abnormal) and the error check result for the signal level of the differential signal including the training data indicates normal (L/H), the initial set differential signal The signal level is controlled upward by a second upward width (eg, 10 mA) lower than the first upward width.

When the error check result for the training data indicates normal, and the error check result for the signal level of the digital signal indicates an error (abnormal) (H/L), the processing unit 120 is the signal of the initially set differential signal. The level (output level of the transmitter 132) is controlled upward by a third upward width (eg, 5 mA) lower than the second upward width.

The third uplink width is set smaller than the second upstream width, because the error check result of the training data is more important than the error check result of the signal level of the differential signal in terms of communication reliability (data integrity). . In other words, if the error check result of the training data indicates that an error has occurred, the output level of the transmitter 132 is increased with a high rise width because normal data communication is not possible, and the data is normal but the margin is insufficient (signal level is insufficient. ), the output level is increased with a relatively small rise width.

On the other hand, if both the error check result of the training data and the error check result of the signal level of the differential signal are normal, the processing unit 110 maintains the signal level of the differential signal set initially or maintains the previously increased rise width. do.

In one embodiment, since the processing unit 120 of the transmission device 100 receives both the error check result for the training data and the error check result for the signal level of the differential signal including the training data from the reception device 200 , As shown in Figure 2, it is preferable to apply to a system in which the receiver 134, Rx of the transmitting device 100 and the transmitter 224, Tx of the receiving device are connected by two TTL lines 172 and 174. something to do.

According to another embodiment, the processor 120 does not individually receive an error check result for the training data and an error check result for a signal level of a differential signal including the training data from the receiving device 200, but the Among the two error check results, only one error check result indicating that at least one of the two error check results indicates an error or both indicates normal is received through the receiver 134.

Here, one error check result may be logical data obtained by logically calculating an error check result for the training data and an error check result for a signal level of a differential signal including the training data. Here, the logical operation may be, for example, an AND operation.

The processing unit 120 controls the output level of the transmitter 132 to adjust the signal level (amplitude level or signal strength) of the differential signal including the data (or actual data) using only one error check result. In this case, although the processing unit 110 can know that an error has occurred, the type of the error cannot be known.

As described above, in the case of another embodiment, since the processing unit 120 cannot know the type of the error, as in the above-described embodiment, the upper width of the output level is not precisely controlled, but is increased step by step with the same upper width. For example, if one error check result of which the type of error is unknown indicates the occurrence of an error, the output level of the initially set differential signal is increased by a fixed upward width (for example, 10mA). If the receiving device 200 performs an error check on the differential signal whose output level has been increased and the error check result is fed back to the transmitting device 100, the error check result further indicates the occurrence of an error, The signal level of the previously raised digital signal is again increased by a fixed upward width (eg, 10mA).

In another embodiment, since the processing unit 120 of the transmitting device 100 receives only one error check result from the receiving device 200, as shown in FIG. 1, the receiver 134 of the transmitting device and the transmitter of the receiving device It may be desirable to apply to a system where 160 is connected by one TTL line 160.

Transceiver(130)

The transceiver 130 includes a transmitter 132 and a receiver 134.

The transmitter 132 processes (or modulates) the training data input from the processing unit 120 to represent a first differential signal representing the training data as a first logic state and a second logic state in which the first logic state is inverted. A differential signal including a second differential signal is generated and transmitted to the receiving device 200 through the differential transmission lines 150 (152 and 154). For example, the transmitter 132 transmits a first differential signal to the reception device 200 through the 1-1 transmission line 152, and the second differential signal through the 1-2 transmission line 154. It transmits to the receiving device 200.

Transmitter 132 may be designed to include a hardware configuration such as a differential amplifier to generate a differential signal.

The transmitter 132 increases the output level of the differential signal under the control of the processing unit 120. For example, the transmitter 132 may increase the output level of the differential signal according to the output level control value input from the processing unit 120.

The output level control value may be a gain value of the differential amplifier or a value for controlling a resistance value of a variable resistor provided in or connected to the differential amplifier.

The receivers 134 and Rx receive a TTL signal representing an error check result from the receiving device 200 and input it to the processing unit 120 and the counting unit 140.

The TTL signal includes a first TTL signal indicating an error check result of training data and a second TTL signal indicating an error check result of a signal level of a differential signal including training data. In this case, the TTL signal line transmitting the TTL signal includes a line 172 transmitting a first TTL signal and a line 174 transmitting a second TTL signal, as illustrated in FIG. 2.

Since the technical focus of the present invention is not on the hardware configuration inside the transmitter 132 or the receiver 134, a description of these will be replaced with a description of a known differential signaling technique and a TTL signaling technique.

Counting (140)

When the error check result received from the receiving device 200 through the transceiver 130 indicates an error, the counting unit 140 counts the number of occurrences of the error and inputs the counting result to the processing unit 110. .

The processing unit 110 stops the upward control of the output level of the differential signal when the number of error occurrences exceeds a preset number (eg, 3 times) according to the counting result of the counting unit 140.

just like this. The reason why the output level of the differential signal is limited is that the output level of the differential signal cannot be increased indefinitely. When the number of error occurrences exceeds the preset number, the processing unit 120 terminates the training mode, and the output level is raised immediately before exceeding the preset number (eg, 3 times). The actual data transmitted in the transmission mode) is configured as a differential signal and transmitted to the receiving device 200.

On the other hand, when the training mode ends, communication based on TTL signaling between the receiver 134 of the transmitting device 100 and the transmitter 224 of the receiving device 200 is no longer performed. This means that the system 300 of the present invention performs bidirectional communication in the training mode, but when the training mode ends (converts to normal data transmission mode), it switches to the original unidirectional communication. Here, switching to one-way communication means that the receiver 134 in the transmitting device 100 and the transmitter 214 in the receiving device 200 connected by a TTL transmission line are deactivated. Deactivation of these 134 and 214 can be realized through power supply cutoff under the control of the processing units 120 and 220 in each device.

Hereinafter, the receiving device 200 will be described in detail.

The receiving device 200 includes a transceiver 210, a processing unit 220, a memory 230, and a signal level measurement unit 240.

Transceiver(210)

The transceiver 210 includes a receiver 212 (Rx) and a transmitter 214 (Tx).

The receiver 212 receives a differential signal from the transmitter 132 of the transmission device 100, subtracts the first differential signal and the second differential signal included in the differential signal, and extracts (or demodulates) training data from the differential signal. And inputs it to the processing unit 220. In addition, the receiver 212 does not subtract the first differential signal and the second differential signal, and inputs the received differential signal to the signal strength measurement unit 240 as it is.

The transmitter 214 processes (modulates) error check data indicating an error check result input from the processing unit 220 to generate a TTL signal, and converts the generated TTL signal to one TTL transmission line (160 in FIG. 1) or 2 TTL transmission lines (172, 174 in FIG. 2) to transmit to the receiver 134 of the transmission device 100.

When the TTL signal is one TTL signal (logical level'H' or'L') that combines the error check result for the training data and the error check result for the signal level of the differential signal (AND operation), the transmitter The 224 transmits one TTL signal (logical level'H' or'L') to the receiver Rx of the transmission device 100 through one TTL transmission line (160 in FIG. 1).

When the TTL signal includes a first TTL signal indicating an error check result for training data and a second TTL signal indicating an error check result for the signal level of the differential signal, the transmitter 224 transmits the first TTL signal TTL The receiver 134 of the transmitting device 100 transmits to the receiver 134 of the transmitting device 100 through a line (172 in FIG. 2), and transmits the second TTL signal through another TTL transmission line (174 in FIG. 2). To send.

Processing unit 220

The processing unit 220 performs an error check on the training data input from the receiver 212.

For error checking of the training data, for example, the processing unit 220 reads the training data stored in the memory 230 and the read training data and the training data transmitted from the transmission device 100 are Check if they match.

If the training data read from the memory 230 and the training data transmitted from the transmission device 100 do not match, the processing unit 220 generates error check data indicating an error occurrence.

For example, if the training data from the transmission device 100 is '101010101010' and the training data read from the memory 230 is '101010101010', the two training data match, so the processor 220 does not generate an error. Generates error check data indicating (normal). If the training data from the transmission device 100 is '101010101110' and the training data read from the memory 230 is '101010101010', the two training data do not match, so the processing unit 220 checks an error indicating an error occurrence. Generate data.

In addition, the processing unit 220 uses the signal amplitude of the differential signal including the training data input from the signal strength measurement unit 240 to provide an error with respect to the signal level (amplitude level or signal strength) of the differential signal. Perform a check.

For example, if the signal amplitude of the differential signal input from the signal strength measurement unit 240 is less than the reference strength, the processing unit 220 generates error check data indicating the occurrence of an error, and otherwise, no error occurs. Generates error check data indicating (normal).

Here, the reference strength is the reference strength for the difference between the amplitude of the first differential signal and the amplitude of the second differential signal, the reference strength for the positive level of the first differential signal, and the second It may include at least one of the reference strength for the amplitude of the differential signal (negative level).

The error check data may be generated in the form of an output indicating the logical state shown in Table 3 or Table 4 below.

Error check result Of error check data
Final output form For training data
Error check result For differential signals
Error check result L L LL L H LH H L HL H H HH

L: No error, H no error

Error check result Of error check data
Final output form For training data
Error check result For differential signals
Error check result L L L L H L H L L H H H

The output form of the error check data in Table 4 is a combination of the error check result for the training data and the error check result for the differential signal.For example, the logic state indicated by the error check result for the training data and the differential signal It may be a result of AND operation on a logic state indicating an error check result.

When the processing unit 220 generates two error check data as shown in Table 3, the two error check data are configured as two TTL signals, and as shown in FIG. 2, two TTL transmission lines (Fig. When two TTL signals are fed back (transmitted) to the transmission device 100 through 172 and 174, and one error check data is generated as shown in Table 4, one error check data is configured as one TTL signal. , As shown in FIG. 1, feedback (transmission) is performed to the transmission device 100 through one TTL transmission line (160 in FIG. 1).

Memory 230

The memory 230 stores training data promised to the transmission device and the reception price, and the memory 230 outputs the stored training data to the processing unit 220 at the request of the processing unit 220.

Signal strength Measuring part (240)

The signal strength measurement unit 240 measures the signal strength of a differential signal composed of training data received through the receiver 212. For example, the signal strength measurement unit 240 includes an amplitude corresponding to a difference between an amplitude of a first differential signal and a negative level of a second differential signal, and an amplitude of the first differential signal. And at least one of the amplitude of the second differential signal (negative level) is measured, and the measurement result is output to the processing unit 220.

3 is a flowchart illustrating a method of adaptively controlling a signal level of a digital signal transmitted from a transmitting device to a receiving device according to an embodiment of the present invention.

Referring to FIG. 3, first, in steps S310 and S320, the transmitting device 100 and the receiving device 200 are each powered on (POWER 0N). When the power is turned on, the transmitting device 100 and the receiving device 200 start operating in the training mode. In the training mode, in addition to the differential transmission line 150, a TTL transmission line (160 in FIG. 1 or 172 and 174 in FIG. 2) is activated. Activation of the TTL transmission line (160 in Fig. 1 or 172 and 174 in Fig. 2) is performed by power supply to the receiver 134 in the transmitting device 100 and the transmitter 214 in the receiving device 200, for example. Can be realized. That is, in the training mode, two-way communication between the transmitting device and the receiving device is possible according to activation of the TTL transmission line (160 in FIG. 1 or 172 and 174 in FIG. 2). When the training mode ends (or switches to the data transmission mode), the TTL transmission line (160 in FIG. 1 or 172 and 174 in FIG. 2) is deactivated, whereby the two-way communication is switched to one-way communication.

Subsequently, in steps S330 and S340, values set in the transmitting device 100 and the receiving device 200 are initialized.

Subsequently, in step S350, the output level (signal level of the differential signal) of the transmitter (132 of FIGS. 1 and 2) is initially set to the minimum value MIN under the control of the processing unit 120 of the transmission device 100.

Next, in step S360, under the control of the processing unit 120 of the transmission device 100, the transmitter 132 of the transmission device 100 configures the training data as a differential signal and transmits the training data to the reception device 200.

Next, in step S370, the receiver 212 of the receiving device 200 receives the differential signal, extracts (demodulates) training data from the received differential signal, and receives the extracted training data from the processing unit of the receiving device 200 ( 220).

Subsequently, in step S380, the processing unit 220 of the receiving device 200 checks an error for the extracted training data (hereinafter referred to as'first error check') and a signal level of a differential signal composed of the training data. Error checks (hereinafter referred to as'second error checks') are each performed to determine whether an error has occurred, and error check data is generated according to the determination result.

According to an embodiment, in the error check data, a first error check result obtained by performing the first error check and a second error check result obtained by performing the second error check are logically calculated (eg, AND operation). It may be logical data obtained through ). For example, when at least one of the first and second error check results indicates an error occurrence, the error check data may be logical data indicating a logical level'L', and the first and second error check results are When all indicate that there is no error, the error check data may be logical data indicating a logic level'H'.

According to another embodiment, the error check data may be logical data indicating a combination of the first error check result and the second error check result. For example, the error check data may be'LL','LH','HL', or'HH' as shown in Table 3.

The processing unit 220 of the reception device 200 generates error check data, outputs it to the transmitter 214 of the reception device 200, and the transmitter 214 configures the error check data as a TTL signal and is shown in FIG. It transmits to the transmission device 100 through one illustrated TTL transmission line or two TTL transmission lines illustrated in FIG. 2.

Subsequently, in step S390, when the error check data transmitted from the receiving device 200 indicates the occurrence of an error, the processing unit 120 of the transmitting device 100 counts the number of error occurrences by +1, and counts the error counted so far. It is determined whether the number of occurrences exceeds the preset number of times N (eg, 3 times). If the number of error occurrences counted so far does not exceed the preset number N, the process proceeds to step S400, and if vice versa, the process proceeds to step S420 to end the training mode. At this time, even if the error check data transmitted from the receiving device 200 indicates no error ('H' or'HH'), the process proceeds to step S420 to end the training mode. Likewise, if the occurrence of an error is not confirmed in step S380 performed by the receiving device 200, the process proceeds to step S430 and the training mode in the receiving device 200 is also terminated.

When the number of error occurrences counted so far exceeds the preset number N and the training mode is terminated, in step S440, the transmitter 132 of the transmission device 100, according to the control of the processing unit 120, the actual data Is configured as a differential signal having an increased signal level immediately before the number of error occurrences exceeds the preset number N and transmitted to the reception device 200. Then, in step S450, the receiving device receives actual data composed of a differential signal.

Similarly, even when the training mode is terminated as the error check data indicates no error ('H' or'HH'), the transmitter 132 of the transmitting device 100 is controlled by the processing unit 120 Accordingly, the actual data is configured as a differential signal having an increased signal level immediately before the error check data indicating no error occurrence ('H' or'HH') is received, and transmitted to the reception device 200.

On the other hand, in step S390, if the number of errors counted so far does not exceed the preset number N, step S400 proceeds, and in step S400, the processing unit 120 of the transmitting device 100 is stored in the memory 110. With reference to the stored upward value adjustment table such as Table 1 or 2, the upward width of the output level (signal level of the differential signal) of the transmitter 132 corresponding to the error check data from the reception device 200 is determined.

At this time, according to an embodiment, the error check data transmitted from the receiving device 200 is a first error check result (error check result for training data) and a second error check result (error check for the signal level of the differential signal). In the case of logical data ('L') obtained by performing a logical operation (eg, AND operation) on the result), the processing unit 120 refers to the upward width adjustment table as shown in Table 2, , 10mA), and in step S410, the transmitter 132 of the transmitting device raises the signal level of the differential signal to a fixed upper width determined by the processing unit 120, and the training data is differential with the raised signal level. It is configured as a signal and transmitted to the receiving device 200.

According to another embodiment, the error check data transmitted from the receiving device 200 is the first error check result (error check result for training data) and the second error check result (error check for the signal level of the differential signal). In the case of logical data ('LL','LH', or'HL') representing a logical combination of results), the processing unit 120 refers to the upward width control table as shown in Table 1 above, and For example, 25mA (LL), 10mA (LH), or 5mA (HL)) is determined, and in step S410, the transmitter 132 of the transmitting device is the differential signal with the upward width determined according to the logical combination by the processing unit 120. The signal level is increased, the training data is configured as a differential signal having the increased signal level, and transmitted to the reception device 200.

The transmission device 100 raises the signal level of the differential signal, the reception device 200 receives training data composed of the increased differential signal, performs an error check thereon, and feedback the error check result back to the transmission device. The steps (S370, S380, S390, S400, and S410) are repeatedly performed until the number of error occurrences exceeds a preset number, and if no error occurs before that, the repetition is immediately terminated and training at the same time. The mode is also ended. When the training mode ends, the TTL transmission line (160 in FIG. 1 and 172 and 174 in FIG. 2) that transmits the error check result by the receiving device 200 to the transmitting device 100 is deactivated, and the transmitting device 100 The communication method between the and the receiving device 200 is switched from two-way communication to one-way communication (or normal data transmission mode) for transmitting actual data. Deactivation of the TTL transmission line means stopping the operation of the receiver 134, which can be realized by cutting off the power supply to the receiver 134 in the transmitting device 100 and the transmitter 214 in the receiving device 200. have.

As described above, the present invention temporarily activates two-way communication between the initialization process and the data transmission process, unlike the existing one-way communication environment in which data transmission is performed immediately after initialization of the transmission device 100 and the reception device 200. By adding a training mode (error check from the receiving device -> feedback of the error check result from the receiving device to the transmitting device -> setting the signal level of the differential signal according to the error check result fed back from the receiving device from the transmitting device) An output design optimized for a communication environment (driving environment) between the 100 and the receiving device 200 is possible, which is advantageous for low power design and electromagnetic wave reduction design. In addition, data integrity can be maintained because it can cope with unexpected and unspecified internal/external noise.

4 to 5 are diagrams showing various system environments to which the present invention can be applied.

In FIG. 4, a system including a transmission device 10 having four transmission ports (Clock, Data0, Data1 and Data2) and a reception device 20 having four reception ports (Clock, Data0, Data1 and Data2) Is shown.

In this system, the transmission ports of the transmitting device 10 and the output ports of the receiving device 20 are connected in a point-to-point manner.

In this system, when an error occurs in the line (15, hereinafter, Data2 line) connecting the output port (Data2) of the transmitting device 10 and the output port (Data2) of the receiving device 20, applying the present invention, For only the Data2 line, the signal level can be raised to a predetermined upward width (for example, 200mV).

In FIG. 5, a system including a transmission device having four serial transmission ports (serial0, serial1, serial2, and serial3) and a plurality of reception devices 42, 44, 46 and 48 having one serial reception port.

A transmission line connecting the serial transmission port (serial3) of the transmission device (30) and the serial reception port (serial3) of the reception device (48) has the largest transmission distance between the transmission device (30) and the reception device (48). When an error occurs at (35), applying the present invention, it is possible to increase the signal level for only the transmission line 35 to a predetermined upward width (eg, 50 mV).

As described above, the present invention can be effectively used in a point-to-point wired communication system by individually increasing the signal level of digital signals transmitted through the output ports of the transmission device.

So far, the present invention has been looked at around the embodiments. Those of ordinary skill in the art to which the present invention pertains will appreciate that the present invention may be implemented in variously modified or modified forms without departing from the essential characteristics of the present invention. Therefore, the disclosed embodiments should be considered from an exemplary point of view for description and not a limiting point of view. The scope of the present invention is shown in the claims rather than the foregoing description, and all differences within the scope equivalent thereto should be construed as being included in the present invention.

Claims (18)

Transmitting device;
Receiving device; And
First and second transmission lines connecting the transmitting device and the receiving device,
The receiving device,
A first digital signal including training data is received from the transmission device through the first transmission line, and an error check is performed on the training data to generate first error check data, and a signal of the first digital signal A second digital signal including third error check data obtained by logically calculating the first error check data and the second error check data is generated by performing an error check on the level to generate second error check data. 2 transmits to the transmitting device through a transmission line,
The transmission device,
The digital signal transmission system for controlling the signal level of the first digital signal upward based on the received third error check data. In claim 1,
The first transmission line is a differential transmission line,
The second transmission line is a digital signal transmission system that is a TTL (Transistor- Transistor Logic) transmission line. In claim 1,
The first digital signal is a differential signal,
The second digital signal is a digital signal transmission system that is a TTL (Transistor- Transistor Logic) signal. In claim 1,
The receiving device,
The digital signal transmission system to obtain the third error check data by AND operation on the first error check data and the second error check data. In claim 1,
The transmission device,
A transmitter for transmitting the first digital signal;
A receiver for receiving the second digital signal;
A memory storing the training data; And
A processing unit that upwardly controls the signal level of the first digital signal according to the logic state of the third error check data included in the second digital signal
Digital signal transmission system comprising a. In claim 5, wherein the processing unit,
The digital signal transmission system for controlling the signal level of the first digital signal upward to a fixed upward width. The method of claim 6, wherein the memory,
Further storing an upward width adjustment table in which the upward width set according to the logic state of the third error check data is stored,
The processing unit,
The digital signal transmission system for controlling the signal level of the first digital signal upward by referring to the upward width adjustment table. The method of claim 1, wherein the receiving device,
A receiver for receiving the first digital signal;
A transmitter for transmitting the second digital signal;
A memory storing the training data; And
An error check is performed on the training data according to whether the training data included in the first digital signal received through the receiver matches the training data stored in the memory, and the first digital signal received through the receiver is A processing unit that compares the signal strength and the reference strength to perform an error check on the signal level of the first digital signal
Digital signal transmission system comprising a. Transmitting device;
Receiving device; And
Including first and second transmission lines connecting the transmitting device and the receiving device,
The receiving device,
A first digital signal including training data is received from the transmission device through the first transmission line, and an error check is performed on the training data to generate first error check data, and a signal of the first digital signal Performs an error check on the level, generates second error check data, and transmits a second digital signal including the first error check data and the second error check data to the transmission device through the second transmission line. Send,
The transmission device,
The digital signal transmission system for controlling the signal level of the first digital signal upward using the first and second error check data transmitted from the receiving device. The method of claim 9, wherein the second transmission line,
A 2-1 transmission line for transmitting the first error check data to the transmission device; And
2-2 transmission line for transmitting the second error check data to the transmission device
Digital signal transmission system comprising a. The method of claim 9, wherein the transmitting device,
The digital signal transmission system for controlling the signal level of the digital signal upward with an upward width set according to a logical combination between the logic state of the first error check data and the logic state of the second error check data. The method of claim 9, wherein the transmitting device,
A transmitter for transmitting the first digital signal;
A receiver for receiving the second digital signal;
A memory storing an upward width adjustment table set according to a logical combination between a logic state of the training data and the first error check data and a logic state of the second error check data;
A signal of the first digital signal with an upward width corresponding to a simple logical combination of a logical state of the first error check data and a logical state of the second error check data received from the receiving device by referring to the upward width adjustment table. Processing unit that controls the level upward
Digital signal transmission system comprising a. The method of claim 12, wherein the processing unit,
If the logical combination indicates that no error has occurred, controlling the end of operation of the receiver to deactivate the second transmission line. Operating the transmitting device and the receiving device in a training mode according to power on;
Transmitting, by the transmitting device, a first digital signal including training data to the receiving device through a first transmission line;
The receiving device receives the first digital signal, performs an error check on the training data to generate first error check data, and performs an error check on the signal level of the first digital signal to perform a second Generating error check data, and transmitting a second digital signal including the first and second error check data to the transmission device through the second transmission line; And
Controlling, by the transmitting device, a signal level of the first digital signal upward by using the first and second error check data included in the received second digital signal
Digital signal transmission method comprising a. The method of claim 14, wherein the upward control step,
And controlling the signal level of the digital signal upward with an upward width set according to a logical combination between the logic state of the first error check data and the logic state of the second error check data. In clause 14,
When both the first and second error check data indicate that no error has occurred, switching the transmitting device and the receiving device from the training mode to the normal data transmission mode
Digital signal transmission method further comprising a. In paragraph 16,
The transmitting device and the receiving device,
Performing two-way communication in the training mode,
Digital signal transmission method to perform one-way communication in the normal data transmission mode. The method of claim 14, wherein the upward control step,
When at least one of the first and second error check data indicates the occurrence of an error and the number of error occurrences counted so far exceeds a preset number, the signal level of the first digital signal is stopped to increase control. Signal transmission method.

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