SPI signal cross-screen transmission method and foldable electronic device

Abstract

The present invention discloses a method for sending SPI signals across screens and a foldable electronic device. In order to reduce the number of cross-screen signal lines when sending SPI signals, after the application processor of the present invention sends the SPI signal, the first under-screen chip delays the SPI clock signal, and obtains the first flip information of the SPI clock signal, the second flip information of the SPI chip select signal, and the third flip information of the SPI data output signal through edge detection; the combination of the first flip information, the second flip information, and the third flip information obtained by the edge detection is encoded to obtain the encoded information, and the encoded information is assembled into frame data; the frame data is sent to the second under-screen chip through the first cross-screen signal line. Then the second under-screen chip recovers the SPI clock signal, the SPI chip select signal, and the SPI data output signal according to the received frame data. The present invention can reduce the number of cross-screen signal lines, and has higher bandwidth and lower latency. The present invention is suitable for the field of signal bridging and conversion.

Description

Technical Field

[0001] The invention relates to the field of signal bridging and conversion, and in particular to a method for sending SPI signals across screens and a foldable electronic device. Background Art

[0002] Foldable electronic devices with dual screens are an emerging electronic product that are popular among some consumers due to their portable design and large screen.

[0003] Since the dual screens use a movable hinge design, the requirements for the cross-screen signal line are high. Long-term repeated opening and closing can easily cause the cross-screen signal line to malfunction, greatly reducing the service life of the electronic device. Therefore, reducing the number of cross-screen signal lines is an urgent need in this field.

[0004] Figure 1 The first screen and the second screen connected by the hinge and the schematic diagram of the Serial Peripheral Interface (SPI) connection scheme are shown. The SPI interface is a full-duplex, synchronous communication bus with the advantages of simplicity and high communication rate.

[0005] The application processor is located under the first screen, and the second screen includes a first sensor and a second sensor. The application processor has two related SPI interfaces: an SPI1 interface and an SPI2 interface. When the SPI1 interface and the SPI2 interface send signals to the first sensor and the second sensor, the information is transmitted directly across the hinge through the cross-screen signal line.

[0006] Since each standard SPI interface includes 4 signal lines, which are usually referred to in the art as: SPI clock signal SPI_SCLK, SPI data output signal SPI_DO, SPI data input signal SPI_DI and SPI chip select signal SPI_CS. Then, Figure 1 The two SPI interfaces included in the example require the design of 8 cross-screen signal lines: SPI1_SCLK, SPI1_DO, SPI1_DI and SPI1_CS belonging to the SPI1 interface; SPI2_SCLK, SPI2_DO, SPI2_DI and SPI2_CS belonging to the SPI2 interface. This method results in a large number of cross-screen signal lines, complex printed circuit board routing and a large occupied area.

[0007] Based on this, how to reduce the number of cross-screen signal lines when sending SPI signals has become a technical problem that needs to be solved urgently in this field. Summary of the invention

[0008] In order to alleviate or partially alleviate the above technical problems, the solution of the present invention is as follows:

[0009] A method for sending SPI signals across screens, wherein a first SPI interface of an application processor sends an SPI clock signal, an SPI chip select signal and an SPI data output signal to a first chip under the screen; after the first chip under the screen delays the SPI clock signal, the first flip information of the SPI clock signal, the second flip information of the SPI chip select signal and the third flip information of the SPI data output signal are obtained through edge detection; a combination of the first flip information, the second flip information and the third flip information obtained through edge detection is encoded to obtain the encoded information, and the encoded information is assembled into frame data; the frame data is sent to a second chip under the screen through a first cross-screen signal line; the second chip under the screen receives the frame data and deframes the frame data to obtain the first flip information of the SPI clock signal, the second flip information of the SPI chip select signal and the third flip information of the SPI data output signal; according to the first flip information, the second flip information and the third flip information obtained after deframing, the second chip under the screen generates an SPI clock signal, an SPI chip select signal and an SPI data output signal.

[0010] Furthermore, after the second under-screen chip generates the SPI clock signal, the SPI chip select signal and the SPI data output signal, the SPI clock signal, the SPI chip select signal and the SPI data output signal are sent to the first device.

[0011] Furthermore, the application processor and the first under-screen chip are located under the first screen, and the second under-screen chip and the first device are located under the second screen.

[0012] Further, the first device is a first sensor.

[0013] Furthermore, the first chip under the screen transmits a clock to the second chip under the screen via the third cross-screen signal line.

[0014] Furthermore, the SPI signal sent by the second SPI interface of the application processor is assembled into several frames of data in the first under-screen chip and then sent to the second under-screen chip through the second cross-screen signal line.

[0015] Furthermore, the first cross-screen signal line and the second cross-screen signal line share a transmission clock.

[0016] Furthermore, the frame data includes start information, encoded information and end information.

[0017] Further, the first cross-screen signal line, the second cross-screen signal line and the third cross-screen signal line are signal lines passing through the hinge.

[0018] A foldable electronic device comprises a first screen and a second screen, wherein the first screen comprises an application processor, and the second screen comprises a first device. According to any one of the above-mentioned methods for sending SPI signals across screens, the application processor sends an SPI signal to the first device.

[0019] The technical solution of the present invention has one or more of the following beneficial technical effects:

[0020] (1) When sending SPI signals, the number of cross-screen signal lines can be reduced.

[0021] (2) Since only signal jump or flip information needs to be transmitted, based on the same line, the bandwidth of the present invention is higher and more information can be transmitted.

[0022] (3) In the conventional scheme, the frame data length is relatively long, while the frame data length of the present invention is shorter and the delay of the transmission signal is lower.

[0023] In addition, other beneficial effects of the present invention will be mentioned in the specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a schematic diagram of connecting an application processor and a sensor via a hinge;

[0025] Figure 2 It is a schematic diagram of an exemplary SPI signal cross-screen transmission scheme of the present invention;

[0026] Figure 3 It is a further schematic diagram of the cross-screen transmission scheme of SPI signals between the first under-screen chip and the second under-screen chip in the present invention;

[0027] Figure 4 It is a flow chart of the SPI signal cross-screen sending method of the present invention. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] In order to clearly describe the technical solutions of the embodiments of the present invention, in the embodiments of the present invention, words such as "first" and "second" are used to distinguish the same or similar items with substantially the same functions and effects. Those skilled in the art can understand that words such as "first" and "second" do not limit the quantity and execution order.

[0030] Figure 2 The schematic diagram of an exemplary SPI signal cross-screen transmission scheme of the present invention is shown. An application processor and a first under-screen chip are arranged under the first screen.

[0031] By way of example, the application processor includes a first SPI interface and a second SPI interface. The first under-screen chip includes a first edge detection module and a second edge detection module.

[0032] The second chip under the screen includes a first edge receiving module and a second edge receiving module. The first chip under the screen transmits a sending clock to the second chip under the screen.

[0033] In addition, the first edge detection module sends first transmission data to the first edge receiving module through the first cross-screen signal line; and the second edge detection module sends second transmission data to the second edge receiving module through the second cross-screen signal line.

[0034] The first SPI interface and the first edge detection module can transmit data to each other, and the second SPI interface and the second edge detection module can transmit data to each other.

[0035] The first device and the second device are two devices located under the second screen. For example, the first device is a first sensor, and the second device is a second sensor. The first sensor and the second sensor here are only exemplary devices, and can also be other types of devices.

[0036] The first sensor and the second under-screen chip can transmit SPI signals to each other, and the second sensor and the second under-screen chip can also transmit SPI signals to each other.

[0037] Signals sent between the first under-screen chip and the second under-screen chip are transmitted through cross-screen signal lines. For example, the sending clock is transmitted through a third cross-screen signal line in addition to the first cross-screen signal line and the second cross-screen signal line.

[0038] Figure 3 A further schematic diagram of the cross-screen transmission scheme of SPI signals between the first under-screen chip and the second under-screen chip in the present invention is shown.

[0039] In the first under-screen chip, an SPI clock signal SPI_SCLK, an SPI chip select signal SPI_CS and an SPI data output signal SPI_DO are received from the first SPI interface of the application processor.

[0040] The SPI clock signal SPI_SCLK is sent to the first edge detection module after passing through the delay module; the SPI chip select signal SPI_CS and the SPI data output signal SPI_DO are also sent to the first edge detection module after passing through a glitch filtering module respectively.

[0041] For example, the delay module delays the input clock signal by 10 to 12 ns. Generally, the data of the previous beat will be sampled in the next beat. The purpose of this technical means is to enable the rising edge of the clock of the current beat to sample the data of the current beat, so that the clock flip and data flip can occur in the same frame of data.

[0042] The first edge detection module is used to detect the flip information in the input signal, and send the first flip information of the SPI clock signal SPI_SCLK, the second flip information of the SPI chip select signal SPI_CS and the third flip information of the SPI data output signal SPI_DO to the framing and sending module, and the framing and sending module encodes the combination of the flip information to obtain the encoded information.

[0043] For example, if the framing and sending module receives the second flip information of the SPI chip select signal SPI_CS, the encoding is "01"; if the framing and sending module receives the first flip information of the SPI clock signal SPI_SCLK, the encoding is "10"; if the framing and sending module receives the first flip information of the SPI clock signal SPI_SCLK and the third flip information of the SPI data output signal SPI_DO, the encoding is "11". In this example, "00" is a reserved encoding.

[0044] Preferably, if the framing and sending module receives the first flip information of the SPI clock signal SPI_SCLK, the framing and sending module only transmits the leading edge information in each cycle.

[0045] For example, the start information, the encoded information and the end information are combined to form a frame of data in the framing and sending module. Several frames of data are used as the first sending data and are sent to the second under-screen chip through the first cross-screen signal line. The cross-screen signal line is a signal line that passes through the hinge.

[0046] Similarly, for the second SPI interface, the SPI signal sent to the second edge detection module is assembled into several frames of data in the first under-screen chip and sent to the second under-screen chip through the second cross-screen signal line as second transmission data.

[0047] After receiving several frames of data, the receiving and deframing module in the second under-screen chip obtains the first flip information of the SPI clock signal SPI_SCLK, the second flip information of the SPI chip select signal SPI_CS and the third flip information of the SPI data output signal SPI_DO after deframing. These flip information are sent to the SPI signal generation module, and the SPI clock signal SPI_SCLK, the SPI chip select signal SPI_CS and the SPI data output signal SPI_DO are generated or restored respectively.

[0048] For example, the SPI clock signal SPI_SCLK, SPI chip select signal SPI_CS and SPI data output signal SPI_DO recovered for the first SPI interface are sent to the first sensor. Correspondingly, the SPI clock signal SPI_SCLK, SPI chip select signal SPI_CS and SPI data output signal SPI_DO recovered from the SPI signal sent through the second SPI interface are sent to the second sensor.

[0049] Figure 4 The flow chart of the SPI signal cross-screen transmission method of the present invention is shown, which specifically includes the following steps:

[0050] First, the first SPI interface of the application processor sends an SPI clock signal, an SPI chip select signal and an SPI data output signal to the first under-screen chip; after the first under-screen chip delays the SPI clock signal, the first flip information of the SPI clock signal, the second flip information of the SPI chip select signal and the third flip information of the SPI data output signal are obtained through edge detection; the combination of the first flip information, the second flip information and the third flip information is encoded to obtain the encoded information, and the encoded information is assembled into frame data.

[0051] Then, the frame data is sent to the second under-screen chip through the first cross-screen signal line.

[0052] Finally, the second chip under the screen receives the frame data and deframes the frame data to obtain the first flip information of the SPI clock signal, the second flip information of the SPI chip select signal and the third flip information of the SPI data output signal; according to the first flip information, the second flip information and the third flip information obtained after deframing, the second chip under the screen generates the SPI clock signal, the SPI chip select signal and the SPI data output signal.

[0053] The above two SPI interfaces use only one cross-screen signal line to send data. The first chip under the screen transmits the sending clock to the second chip under the screen through the third cross-screen signal line. The first cross-screen signal line and the second cross-screen signal line share the sending clock.

[0054] In other words, the present invention can achieve the purpose of sending SPI signals through one SPI interface by only two signal lines, and can achieve the purpose of sending SPI signals through two SPI interfaces by only three signal lines. For n SPI interfaces to send SPI signals, only n+1 signal lines are needed, where n is a positive integer.

[0055] In order to better illustrate the present invention, numerous specific details are provided in the above specific embodiments. It should be understood by those skilled in the art that the present invention can also be implemented without certain specific details. In some examples, methods, means, components and circuits well known to those skilled in the art are not described in detail in order to highlight the subject matter of the present invention.

[0056] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A method for sending SPI signals across screens, characterized in that: The first SPI interface of the application processor sends an SPI clock signal, an SPI chip select signal and an SPI data output signal to the first under-screen chip; After the first chip under the screen delays the SPI clock signal, first flip information of the SPI clock signal, second flip information of the SPI chip select signal and third flip information of the SPI data output signal are obtained through edge detection; Encode the combination of the first flip information, the second flip information and the third flip information obtained by edge detection to obtain encoded information, and assemble the encoded information into frame data; Sending the frame data to the second under-screen chip via the first cross-screen signal line; The second under-screen chip receives the frame data and deframes the frame data to obtain first flip information of the SPI clock signal, second flip information of the SPI chip select signal, and third flip information of the SPI data output signal; According to the first flip information, the second flip information and the third flip information obtained after deframing, the second under-screen chip generates an SPI clock signal, an SPI chip select signal and an SPI data output signal; The first chip under the screen transmits a clock to the second chip under the screen via the third cross-screen signal line; The first cross-screen signal line and the second cross-screen signal line share a transmission clock.

2. The SPI signal cross-screen sending method according to claim 1, characterized in that: After the second under-screen chip generates the SPI clock signal, the SPI chip select signal and the SPI data output signal, the SPI clock signal, the SPI chip select signal and the SPI data output signal are sent to the first device.

3. The SPI signal cross-screen sending method according to claim 2, characterized in that: The application processor and the first under-screen chip are located under the first screen, and the second under-screen chip and the first device are located under the second screen.

4. The SPI signal cross-screen sending method according to claim 3, characterized in that: The first device is a first sensor.

5. The SPI signal cross-screen sending method according to claim 4, characterized in that: The SPI signal sent by the second SPI interface of the application processor is assembled into several frames of data in the first under-screen chip, and then sent to the second under-screen chip through the second cross-screen signal line.

6. The SPI signal cross-screen transmission method according to claim 5, characterized in that: The frame data includes start information, encoded information and end information.

7. The SPI signal cross-screen transmission method according to claim 6, characterized in that: The first cross-screen signal line, the second cross-screen signal line and the third cross-screen signal line are signal lines passing through the hinge.

8. A foldable electronic device, comprising a first screen and a second screen, wherein the first screen comprises an application processor, and the second screen comprises a first device, wherein: According to the method for sending SPI signals across screens according to any one of claims 1 to 7, the application processor sends the SPI signal to the first device.

Images