CN103118237A - Interface circuit of image receiving device and data transmission method thereof - Google Patents

Abstract

An interface circuit of an image receiving device and a data transmission method thereof are provided, the interface circuit of the image receiving device comprises a plurality of signal transmission units, each signal transmission unit is provided with a first signal receiving end and a second signal receiving end, and the first signal receiving end and the second signal receiving end respectively receive a first input signal and a second input signal. Each signal transmission unit compares the first input signal and the second input signal to generate a comparison result, and outputs the first input signal and the second input signal and/or the comparison result according to a set mode.

Description

Interface circuit of image receiving device and data transmission method thereof

technical field

The invention relates to an interface circuit, in particular to an interface circuit of an image receiving device and a data transmission method thereof.

Background technique

With the advancement of process technology, the image quality obtained by the CMOS detector (sensor) used for image acquisition has been greatly improved. Moreover, under the condition that the cost of the CMOS detector is decreasing day by day, the CMOS detector has become a market mainstream product of another image detector besides the charge coupled device (CCD) detector.

In addition, CMOS detectors have different output interface circuits when they are applied in different fields. Taking the field of mobile phones as an example, the circuit interface used by CMOS detectors is based on Mobile Industry Processor Interface, MIPI ) is the mainstream, while in camera applications, the use of sub-low voltage differential signal (Sub Low Voltage Differential Signal, sub-LVDS) circuit interface is the mainstream. In addition, in a digital video (Digital Video, DV) camera or an image acquisition device using a charge-coupled device detector, the transmission interface of the parallel bus is the main axis. That is to say, to develop an interface circuit that can be commonly used in the above-mentioned various specifications, it is necessary to design an interface circuit with many input and output pins, so that the interfaces of various specifications can use many of them separately. A pin to complete the action of data transmission. Such an interface circuit will increase the circuit area due to too many input and output pins, and increase the manufacturing cost of the interface circuit.

Contents of the invention

The invention provides an interface circuit of an image receiving device, which provides the transmission action of multiple image input signals in different formats.

The invention provides a data transmission method of an input signal interface circuit, which is suitable for an image receiving device to transmit image input signals of different formats.

The present invention proposes an interface circuit of an image receiving device, which includes a plurality of signal transmission units, each signal transmission unit has a first and a second signal receiving end, and the first and second signal receiving end respectively receive the first input signal and the second signal receiving end. input signal. Each signal transmission unit compares the first and second input signals to generate a comparison result, and each signal transmission unit outputs the first and the second input signal and/or the comparison result according to a set mode.

In an embodiment of the present invention, each of the above-mentioned signal transmission units includes a first buffer, a second buffer, and a comparator. The first buffer is coupled to the first signal receiving end to receive the first input signal, and determines whether to output the first input signal according to the setting mode. The second buffer is coupled to the second signal receiving end to receive the second input signal, and determines whether to output the second input signal according to the setting mode. The comparator is coupled to the first and second signal receiving ends, and receives and compares the first and second input signals to generate a comparison result. The comparator determines whether to output the comparison result according to the setting mode.

In an embodiment of the present invention, each of the above-mentioned signal transmission units includes a first buffer, a second buffer comparator, and a selector. The first buffer is coupled to the first signal receiving end to receive the first input signal. The second buffer is coupled to the second signal receiving end to receive the second input signal. The comparator is coupled to the first and second signal receiving ends, receives and compares the first and second input signals, and generates a comparison result. The selector is coupled to the first and second buffers and the output terminals of the comparator, and selects and outputs the first and second input signals and/or the comparison result according to the setting mode.

In an embodiment of the present invention, it further includes a setting mode generator. The setting mode generation is coupled to the signal transmission unit and used for generating the setting mode.

In an embodiment of the present invention, the above-mentioned first signal and the second signal are differential signals.

In an embodiment of the present invention, the aforementioned setting modes include a differential transmission mode, a parallel transmission mode and a common transmission mode.

In an embodiment of the present invention, when the above-mentioned setting mode is the differential transmission mode, each signal transmission unit outputs the comparison result; when the above-mentioned setting mode is the parallel transmission mode, each signal transmission unit outputs the first and For the second input signal, when the above-mentioned setting mode is the common transmission mode, each signal transmission unit outputs the first and second input signals and the comparison result.

The present invention also proposes a data transmission method for an input signal interface circuit, which is suitable for an image receiving device. The steps include: first, receiving a plurality of first input signals and a plurality of second input signals; The two input signals are compared to generate multiple comparison results; finally, the first and second input signals and/or the comparison results are output according to the setting mode.

Based on the above, the present invention proposes to use a plurality of signal transmission units, and each signal transmission unit selects and outputs the received first and second input signals according to a preset setting mode and/or according to the first and second input signals The resulting comparison results. In this way, the input signals generated by image acquisition devices with multiple different formats can be transmitted to the image receiving device through a single interface circuit, effectively saving required hardware costs without using multiple different interface circuits.

In order to make the above-mentioned features and advantages of the present invention more comprehensible, the following specific embodiments are described in detail with reference to the accompanying drawings.

Description of drawings

FIG. 1 shows a schematic diagram of an interface circuit 100 of an image receiving device according to an embodiment of the present invention.

FIG. 2 shows a schematic diagram of an interface circuit 200 of an image receiving device according to an embodiment of the present invention.

FIG. 3A shows a schematic diagram of an implementation of the signal transmission unit 101 of the embodiment of the present invention.

FIG. 3B shows a schematic diagram of another implementation of the signal transmission unit 101 of the embodiment of the present invention.

Figure 4 shows a flow chart of a data transmission method for an input signal interface circuit

Reference signs:

100, 200: interface circuit

101～10N, 201～20N: signal transmission unit

TI11～TIN2: signal receiving end

IN11～INN2: input signal

OUT1～OUTN: output signal

MS: setting mode

210: set pattern generator

BUF1, BUF2: buffers

CMP1: Comparator

OUT11, OUT13: output signal

OUT12: comparison result

1011: selector

S410～S430: steps of the data transmission method

Detailed ways

Please refer to FIG. 1 below. FIG. 1 shows a schematic diagram of an interface circuit 100 of an image receiving device according to an embodiment of the present invention. The interface circuit 100 includes a plurality of signal transmission units 101˜10N, wherein N is a positive integer. The signal transmission units 101 - 10N respectively have signal receiving terminals TI11 - TIN2 , and the signal receiving terminals TI11 - TIN2 are respectively used for receiving input signals IN11 - INN2 . Taking the signal transmission unit 101 as an example, the signal transmission unit 101 has two signal receiving terminals TI11 and TI12 . The signal transmission unit 101 receives the input signal IN11 through the signal receiving terminal TI11 , and receives the input signal IN12 through the signal receiving terminal TI12 .

In this embodiment, the input signals IN11 - INN2 are signals generated by correspondingly connected image acquirers to the image receiving device to which the interface circuit 100 belongs. Therefore, the format of the input signals IN11˜INN2 is the same as that used by the image acquirer. That is to say, the input signals IN11˜INN2 can be one of the transmission formats of Mobile Industry Processor Interface (MIPI), Sub-Low Voltage Differential Signaling (sub-LVDS) and Parallel Bus.

The signal transmission units 101 - 10N respectively compare the received input signals IN11 - INN2 to generate comparison results. In addition, the signal transmission units 101 - 10N respectively output the received input signals IN11 - INN2 and/or the generated comparison results as the output signals OUT1 - OUTN according to the setting mode. Specifically, taking the signal transmission unit 101 as an example, the signal transmission unit 101 compares the voltages of the input signals IN11 and IN12 , and generates a comparison result according to the comparison result of the input signals IN11 and IN12 .

To put it simply, if the signal receiving terminal TI11 is set as a positive input terminal and the signal receiving terminal TI12 is set as a negative input terminal, the signal transmission unit 101 can generate Comparison result of logic high level. In other words, when the signal transmission unit 101 determines that the voltage of the input signal IN11 is lower than the input signal IN12 , it can generate a logic low level comparison result. Moreover, the signal transmission unit 101 generates the output signal OUT1 according to the setting mode.

In this embodiment, the setting mode includes a differential transmission mode, a parallel transmission mode, and a shared transmission mode. When the setting mode is equal to the differential transmission mode, it means that the input signal IN11 and the input signal IN12 are differential signals. The output signal OUT1 generated by the signal transmission unit 101 is a comparison result of the input signal IN11 and the input signal IN12 . In addition, when the setting mode is equal to the parallel transmission mode, the signal transmission unit 101 directly transmits the input signal IN11 and the input signal IN12 as the output signal OUT1 . When the setting mode is equal to the common transmission mode, the signal transmission unit 101 transmits the input signal IN11 , the input signal IN12 , and the comparison result of the input signal IN11 and the input signal IN12 as the output signal OUT1 .

Please note that when the circuit interface used by the image detector is a mobile industrial processor interface, the setting mode is equal to the common transmission mode, and when the circuit interface used by the image detector is a sub-low voltage differential signal, the setting mode is It is equal to the differential transmission mode, and when the circuit interface used by the image detector is the transmission interface of the parallel bus, the setting mode is equal to the parallel transmission mode.

Please refer to FIG. 2 below. FIG. 2 shows a schematic diagram of an interface circuit 200 of an image receiving device according to an embodiment of the present invention. The interface circuit 200 includes a plurality of signal transmission units 201 - 20N and a setting mode generator 210 , wherein N is a positive integer. In this embodiment, the setting mode generator 210 is used to generate the setting mode MS, and provide the setting mode MS to the signal transmission units 201˜20N. The setting mode generator 210 can generate the setting mode MS according to a software setting method or a hardware setting method.

Specifically, the setting mode generator 210 can be configured by the user through the software interface of the application program, and is capable of generating the setting mode MS. Alternatively, the setting mode generator 210 can also set the setting mode MS to be generated by means of a pin option. The so-called pin option method is to set different setting modes MS by adding logic high or low level voltage values to multiple selection pins of the interface circuit 200 respectively. Taking the setting mode MS as an example with two pins, it can generate four choices of "00", "01", "10" and "11" (where 0 represents the logic low level voltage applied to the pin, 1 Represents the logic high level voltage applied to the pin).

Of course, the setting mode generator 210 can also be a non-volatile memory, and the setting mode MS is stored in the setting mode generator 210 by programming, and then the setting mode MS is transmitted to the signal transmission Units 201-20N. And when the setting mode MS is to be changed, it can be completed by rewriting a new setting mode MS into the setting mode generator 210 .

Please refer to FIG. 3A below. FIG. 3A shows a schematic diagram of an implementation of the signal transmission unit 101 according to the embodiment of the present invention. The signal transmission unit 101 includes buffers BUF1, BUF2 and a comparator CMP1. The buffer BUF1 is coupled to the signal receiving terminal TI11 to receive the input signal IN11. The buffer BUF2 is coupled to the signal receiving terminal TI12 to receive the input signal IN12. The comparator CMP1 is coupled to the signal receiving terminals TI11 and TI12 for receiving and comparing the input signals IN11 and IN12 to generate a comparison result OUT12 . Please note that the buffers BUF1, BUF2 and the comparator CMP1 jointly receive the setting mode MS. The buffers BUF1 , BUF2 , and the comparator CMP1 respectively determine whether to provide the output signals OUT11 , OUT13 and the comparison result OUT12 generated by them according to the setting mode MS to become the output signal OUT1 of the signal transmission unit 101 .

It is worth noting that the buffers BUF1, BUF2 and the comparator CMP1 will decide whether to provide the output signals OUT11, OUT13 and OUT12 generated by them according to the setting mode MS, and will moderately adjust the input signal IN11 according to the setting mode MS And the electrical characteristics of IN12 to generate output signals OUT11, OUT13. In simple terms, when the setting mode MS is equal to the mobile industrial processor interface, the buffers BUF1, BUF2 and the comparator CMP1 provide the output signals OUT11 and OUT13 conforming to the electrical characteristics specified by the mobile industrial processor interface according to the setting mode MS and OUT12. When the setting mode MS is equal to the sub-low voltage differential signal, the comparator CMP1 provides the output signal OUT12 conforming to the electrical characteristics specified by the sub-low voltage differential signal according to the setting mode MS. When the setting mode MS is equal to the transmission format of the parallel bus, the buffers BUF1 and BUF2 provide the output signals OUT11 and OUT13 according to the electrical characteristics specified by the transmission format of the parallel bus according to the setting mode MS.

Please refer to FIG. 3B below. FIG. 3B shows a schematic diagram of another implementation of the signal transmission unit 101 according to the embodiment of the present invention. In this embodiment, the signal transmission unit 101 includes buffers BUF1 and BUF2 , a comparator CMP1 and a selector 1011 . The buffer BUF1 is coupled to the signal receiving terminal TI11 to receive the input signal IN11. The buffer BUF2 is coupled to the signal receiving terminal TI12 to receive the input signal IN12. The comparator CMP1 is coupled to the signal receiving terminals TI11 and TI12 for receiving and comparing the input signals IN11 and IN12 to generate a comparison result. The selector 1011 is coupled to the buffers BUF1 , BUF2 and the output terminal of the comparator CMP1 , and receives the setting mode MS. The selector 1011 selects to output the comparison result generated by the comparator CMP1 or the outputs of the buffers BUF1 and BUF2 according to the setting mode MS, or simultaneously output the comparison result generated by the comparator CMP1 and the outputs of the buffers BUF1 and BUF2.

Here, in addition to selecting the output generated by the buffers BUF1, BUF2 and the comparator CMP1 to generate the output signal OUT11, the selector 1011 also adjusts the electrical characteristics of the output signal OUT11 according to the setting mode MS to make the output The signal OUT11 may conform to the electrical characteristics of the mode specified by the setting mode MS.

Please refer to FIG. 4 below. FIG. 4 shows a flowchart of a data transmission method of an input signal interface circuit, which is applicable to an image receiving device. The steps of the data transmission method include: first, receiving a plurality of first input signals and a plurality of second input signals (S410); then, comparing the first and second input signals respectively to generate a plurality of comparison results (S420 ); and then output the first and second input signals and/or comparison results according to the setting mode. As for the action details of performing the steps of the above data transmission method, the previous embodiments and the manner thereof have been introduced in detail, and will not be described in detail below.

To sum up, the present invention uses the signal transmission unit to compare the received input signals, and outputs the received input signals and/or the comparison result according to the set mode. In this way, the interface circuit of the image receiving device can receive multiple image signals of different specifications with fewer pins. The circuit cost of the image receiving device is effectively reduced.

Although the present invention has been disclosed above with the embodiments, it is not intended to limit the present invention, and any person of ordinary skill in the art may make some changes and modifications without departing from the spirit and scope of the present invention.

Claims (12)

1. An interface circuit of an image receiving device, comprising: A plurality of signal transmission units, each of the signal transmission units has a first and a second signal receiving end, the first and the second signal receiving end respectively receive a first input signal and a second input signal, each of the signal The transmission unit compares the first and the second input signal to generate a comparison result, and each of the signal transmission units outputs the first and the second input signal and/or the comparison result according to a setting mode. 2. The interface circuit of the image receiving device according to claim 1, wherein each of the signal transmission units comprises: a first buffer, coupled to the first signal receiving end to receive the first input signal, and determine whether to output the first input signal according to the setting mode; a second buffer, coupled to the second signal receiving end to receive the second input signal, and determine whether to output the second input signal according to the setting mode; and A comparator, coupled to the first and the second signal receiving end, receives and compares the first and the second input signal, and thereby generates the comparison result, and the comparator determines the output according to the setting mode The comparison result or not. 3. The interface circuit of the image receiving device according to claim 1, wherein each of the signal transmission units comprises: a first buffer, coupled to the first signal receiving end to receive the first input signal; a second buffer, coupled to the second signal receiving end to receive the second input signal; a comparator, coupled to the first and the second signal receiving ends, receives and compares the first and the second input signals, and generates the comparison result; and A selector, coupled to the first and second buffers and the output end of the comparator, selects and outputs the first and second input signals and/or the comparison result according to the setting mode. 4. The interface circuit of the image receiving device according to claim 1, further comprising: A setting mode generator is coupled to the signal transmission units for generating the setting mode. 5. The interface circuit of an image receiving device according to claim 1, wherein the first input signal and the second input signal are differential signals. 6. The interface circuit of an image receiving device according to claim 1, wherein the setting mode includes a differential transmission mode, a parallel transmission mode and a common transmission mode. 7. The interface circuit of an image receiving device according to claim 6, wherein when the set mode is the differential transmission mode, each of the signal transmission units outputs the comparison result, and when the set mode is the parallel transmission mode When the setting mode is the common transmission mode, each of the signal transmission units outputs the first and the second input signals and the comparison result. 8. A data transmission method for an input signal interface circuit, suitable for an image receiving device, comprising: receiving a plurality of first input signals and a plurality of second input signals; comparing the first and the second input signals respectively to generate a plurality of comparison results; and Outputting the first and the second input signals and/or the comparison results according to a setting mode. 9. The data transmission method according to claim 8, wherein the setting mode is generated according to a software setting method or a hardware setting method. 10. The data transmission method according to claim 8, wherein each of the first input signals and each of the corresponding second input signals are differential signals. 11. The data transmission method according to claim 8, wherein the set mode comprises a differential transmission mode, a parallel transmission mode and a common transmission mode. 12. The data transmission method according to claim 11, wherein when the set mode is the differential transmission mode, each of the signal transmission units outputs the comparison result, and when the set mode is the parallel transmission mode, each The signal transmission unit outputs the first and the second input signal, and when the setting mode is the common transmission mode, each of the signal transmission units outputs the first and the second input signal and the comparison result.

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