This application claims priority under 35 U.S.C. § 119 to Korean Patent Application No. 10-2018-0064769 filed on Jun. 5, 2018, the subject matter of which is hereby incorporated by reference.
The inventive concept relates to electronic devices including a display device. More particularly, the inventive concept relates to apparatuses and methods for controlling interface circuitry between a timing controller and a display driver.
A display device such as a liquid crystal display (LCD) device, a plasma display panel (PDP) device, or a light-emitting diode (LED) device usually includes a display driver integrated circuit (hereinafter, “DDI”) that may be used to drive the operation of the display panel. The DDI is a semiconductor chip that is used to drive a huge number of pixels constituting the display device. The DDI controls the operation of these pixels by transferring one or more control signals to create a desired visual image on the display device. Contemporary display devices may include high resolution (e.g., 8K or higher) display panels requiring the use of multiple DDIs (e.g., 24 DDIs in the case of a typical 8K/1G1D display panel).
Respective DDIs may be provided on the display device as separate chips, where each chip may be used to drive a portion of the display panel in response to display data provided by a timing controller. In a commonly used interface approach the timing controller is connected to respective DDIs through a high-speed main link or “data line”. However, this interface approach may prove inadequate when a “command” (e.g., an equalizer setting, a bias current setting, a port selection operation, etc.) is communicated (or transferred) from the timing controller to a DDI through the data line, and this inadequacy may be particularly pronounced when the command being transferred is directed to the operation of the data line itself.
Embodiments of the inventive concept provide an interface approach whereby a command is transferred from the timing controller to a selected DDI using a shared channel. However, embodiments of the inventive concept are not limited to the above-described technical problems, and other technical problems can be deduced from the following embodiments.
In one embodiment, the inventive concept provides an electronic device including: a timing controller that generates a command to-be-sent to a display driver integrated circuit (DDI) selected from among a plurality of display driver integrated circuits (DDIs) connected to the timing controller through data lines and a shared channel, wherein the DDI is selected by a DDI control signal transferred from the timing controller to the DDI through a corresponding data line among the data lines, and the command is transferred from the timing controller to the DDI through the shared channel.
In another embodiment, the inventive concept provides a method of interfacing between a timing controller and a plurality of display driver integrated circuits (DDIs) connected to the timing controller through data lines and a shared channel. The method includes; using the timing controller to generate a command to-be-sent to a display driver integrated circuit (DDI) selected from among the DDIs, detecting a command entry state in response to the generating of the command and upon detecting the command entry mode, entering a command reception mode, and during the command reception mode, selecting the DDI using a DDI control signal transferred to the DDI through one of the data lines connecting the timing controller with the DDI, and transferring the command from the timing controller to the DDI through the shared channel.
In another embodiment, the inventive concept provides a display device including: an application processor, a display panel, and a display driver integrated circuit package configured to receive a signal output from the application processor and to convert the received signal to a signal for controlling the display panel. The display driver integrated circuit package include; a timing controller, and display driver integrated circuits (DDIs) connected to the timing controller through data lines and a shared channel. The timing controller generates a command to-be-sent to a display driver integrated circuit (DDI) selected from among DDIs, the DDI is selected by a DDI control signal transferred from the timing controller to the DDI through a corresponding data line among the data lines, and the command is transferred from the timing controller to the DDI through the shared channel.
The above and other objects and features of the inventive concept will become apparent by describing in detail exemplary embodiments thereof with reference to the accompanying drawings.
Embodiments of the inventive concept will now be described in some additional detail with reference to the accompanying drawings. However, the scope of the inventive concept is not limited to only the illustrated and described embodiments.
The electronic device 1000 may be variously implemented as a separate device or as part of a display device (e.g., an LCD device, an LED display device, an OLED display device, or an active matrix OLED display device). In certain embodiments of the inventive concept, the electronic device 1000 may be implemented as a device or part of a device that provides the circuitry and/or components necessary to performing the functions of a DDI, multiple DDIs, whether those DDIs are separately of collectively packaged.
In the illustrated example of
The timing controller 1200 may control the performing of various operations by one or more of the DDIs 1400, such as aligning externally supplied data. In this regard, the timing controller 1200 may convert a signal received from an application processor (not shown) into a corresponding DDI control signal that may be decoded by the DDIs 1400, and provide the DDI control signal to at least one of the DDIs 1400.
In the illustrated example of
In certain embodiments of the inventive concept, a differential signaling approach may be used to transferring data through the respective data lines DL1 to DLn. As will be appreciated by those skilled in the art, a voltage swing for signals being transferred through the data lines may be reduced by using a differential signaling approach, thereby also reducing the level of electromagnetic interference (EMI) and potentially improving the overall rate of data transfer to a display panel. Possible differential signaling approaches that may be used in various embodiments of the inventive concept may include; a reduced swing differential signaling (RSDS) adopting a multi-drop approach, a mini-LVDS (Low Voltage Differential Signaling) approach, and a point-to-point differential signaling (PPDS) approach adopting. However, the inventive concept is not limited to only these examples.
Each of the DDIs 1400 may include a circuit (e.g., a delay locked loop (DLL) circuit or a phase locked loop (PLL) circuit) that recovers a clock signal. In this regard, the DDIs 1400 may respectively receive a clock training pattern from the timing controller 1200 through the data lines DL1 to DLn and perform a training operation based on the received training pattern.
As further illustrated in the example of
“State information” for the respective DDIs 1400 may be transferred from the DDIs 1400 to the timing controller 1200 through the first shared channel SC1. In certain embodiments of the inventive concept, the DDIs 1400 may transfer state information indicating whether a clock is unlocked or locked to the timing controller 1200 through the first shared channel SC1. Accordingly, the timing controller 1200 may recognize whether a clock is locked/unlocked on the basis of these signal(s) received through the first shared channel SC1 and provide, as necessary, a clock training pattern to one or more of the DDIs 1400.
Alternatively or additionally, state information transferred between the DDIs 1400 and the timing controller 1200 though the first shared channel SCI may include environmental and/or performance information (e.g., various settings for the DDIs 1400, bit error rate information, temperature information, touch panel conditions and/or settings, luminance settings, luminance information, etc.).
In certain embodiments of the inventive concept, various signal(s) transferred through the first shared channel SC1 between the timing controller 1200 and one or more of the DDIs 1400 may be open-drain type signal responsive to (or controlled in its operative characteristics by) a corresponding pull-up resistor. Hence, the voltage level of such signal(s) may be accurately controlled (or adjusted) using the pull-up resistor.
The electronic device 1000 may define a training period for the DDIs 1400 by transferring a corresponding “training signal” from the timing controller 1200 to the DDIs 1400 through the second shared channel SC2. In certain embodiments of the inventive concept, the electronic device 1000 may enable the performing (or execution) of a defined training operation by one or more of the DDIs 1400 (e.g., when the training signal is logically low (hereafter, “low”)), or enable the performing of various data processing operation(s) (e.g., when the training signal is logically high (hereafter, “high”)).
The timing controller 1200 and the DDIs 1400 may cooperate to perform a variety of data processing and/or control operation(s) that may involve an what is hereafter referred to as an “interface operation.” An interface operation may be performed using the data lines DL1 to DLn, the first shared channel SC1, and/or the second shared channel SC2. As will be appreciated by those skilled in the art, various data processing and data transfer (including one or more interface operations) may be performed in response to one or more commands. There are usually a variety of possible commands that may be transferred from the timing controller 1200 to the DDIs 1400 through the data lines DL1 to DLn that may have a direct influence on the operating characteristics of the DDIs 1400 (e.g., command(s) changing an equalizer setting, a bias current setting, a port selection, etc.). Such commands signals may include various “write” commands setting (or defining) control values for the DDIs 1400 and/or “read” commands interrogating control values. Hence, because the command being transferred may influence the operating characteristics of one or more of the data lines DL1 to DLn, a higher likelihood of transfer error arises. Additionally, since the voltage swing range for signals being transferred through the data lines DL1 to DLn is relatively small, commands being transferred via the data lines DL1 to DLn may prove particularly susceptible to noise affecting the data lines DL1 to DLn.
According to embodiments of the inventive concept, the electronic device 1000 of
Referring to
Also in
For example, the DDI control signal shown in
A waveform 2700 represents a “command signal” that may be transferred through the first shared channel SC1. Here again, those skilled in the art will recognize that other types of signal(s) may be transferred from the timing controller 1200 to the one or more of the DDIs 1400 through the first shared channel SC1.
Referring to
After execution of the initialization operation (S3200), the electronic device 1000 determines whether a “command entry state” is detected (S3400). For example, the command entry state may be detected when one or more of the DDIs 1400 recognizes that a command is pending (i.e., is “to-be-sent”) from the timing controller 1200. In this regard, the command entry state may be determined in response to one or more signals transferred through the first shared channel SC1 and/or second shared channel SC2.
The electronic device 1000 may determine that the command entry state is indicated (or detected) by interrogating signals (e.g.) on the first shared channel SC1 and the second shared channel SC2 in relation a defined command reception condition. For example, a “command reception condition” may be indicated when the training signal on the second shared channel SC2 is rising (e.g., transitioning from low to high at time T1) while the logical state of the command signal on the first shared channel SC1 is low. However defined in relation to various embodiments of the inventive concept, an indication of a command reception condition may be recognized by one or more of the DDIs 1400. In contrast to the foregoing, exemplary indication of a command reception condition at time T1 in
Upon determining that a command entry state is detected in the method of
In this regard, the operating mode of DDIs 1400 may also be changed in response to detection of a command reception mode. For example, during a time period defined by the command reception mode, the DDIs 1400 may operate in response to an internally generated clock rather than a clock recovered by operation of respective clock recovery circuit(s). The foregoing mode change may occur in deference to reliability considerations for data input to and/or output from the DDIs 1400 during a time in which possible mismatches in clock frequencies may arise between the timing controller 1200 and the DDIs 1400 (e.g., a time period extending from an end of a training operation to receipt of the command).
Thus, during the command reception mode, the electronic device 1000 may select at least one DDI among the DDIs 1400 to receive the command. As previously noted, differential signaling (e.g., a combination of P signal and N signal) may be used to transfer data to the DDIs 1400 through the data lines DL1 to DLn. The selected DDI may be determined in response to a combination of the P signal and the N signal which each of the DDIs 1400 receives through a respective one of the data lines DL1 to DLn.
In certain embodiments of the inventive concept the differential signal may correspond to a chip select condition for the respective DDIs. A chip selection condition (or data state) for one or more of the data lines DL1 to DLn may be indicated by the differential signal. For example a first data state shown in
Returning again to
It should be noted at this point that transfer of a command to other DDIs (e.g., DDI1, DDI3, and/or DDIn) is not precluded by the exemplary waveform shown in
Returning again to
The transfer of a command to the DDIs 1400 may end when a current frame ends (i.e., when a next training operation is performed). Thus, when a current frame ends the electronic device 1000 may again perform the training operation on the DDIs 1400, and a clock locking signal associated with the DDIs 1400 may be provided. However, even before a current frame ends, the transfer of a command to each of the DDIs 1400 may individually (or respectively) ended in response to a corresponding DDI control signal transferred through one of the data lines DL1 to DLn (e.g., a deselect pattern).
Here again, the first and second shared channels SC1 and SC2 are commonly connected to the DDIs 1400. Waveform 5100 represents a training signal transferred to the DDIs 1400 through the second shared channel SC2, and waveform 5700 represents a command signal that is transferred through the first shared channel SC1 to at least the first DDI DDI1 and the second DDI DDI2. Waveform 5300 represents a first DDI control signal transferred through the first data line DL1 to the first DDI DDI1, and waveform 5500 represents a second DDI control signal transferred through the second data line DL2 to the second DDI DDI2.
At time T1, since the training signal on the second shared channel SC2 is rising and the command signal on the first shared channel SC1 is low, the first DDI DDI1 and the second DDI DDI2 recognize that a command is pending from the timing controller 1200.
During a first period 5200, the first DDI DDI1 receives a high P signal and a low N signal through the first data line DL1. Accordingly, the differential signal on the first data line DL1 satisfies the chip select condition and the first DDI DDI1 may receive a first command (e.g., a write command) through the first shared channel SC1.
Once the first command is received and during a subsequent second period 5400, a deselect pattern signal for deselecting the first DDI DDI1 is transferred to the first DDI DDI1 through the first data line DL1. That is, one of “DC 0”, “weakly pull-up”, or “weakly pull-down” states, as described with reference to
During a third period 5600 following the first period, the second DDI DDI2 may receive a high P signal and a low N signal through the second data line DL2. Accordingly, during the third period 5600 in which a differential signal on the second data line DL2 satisfies the chip select condition, the second DDI DDI2 may receive a second command (e.g., a write command) through the first shared channel SC1. Once the second command is completely received, during a fourth period 5800 following the third period 5600, a deselect pattern signal for deselecting the second DDI DDI2 may be transferred to the second DDI DDI2 through the second data line DL2.
Finally, at time T2, when the training signal on the first shared channel SC1 again rises but the command signal on the second shared channel SC2 not low, the electronic device 1000 it may be determined that a current state is not the command entry state.
From the foregoing embodiment those skilled in the art will recognize that the timing controller 1200 may independently transfer command(s) to the DDIs 1400 by selectively defining the nature and timing of DDI control signals respectively applied to the data lines DL1 to DLn.
Referring to
A data signal output from the application processor 6200 may be transferred to the DDI package 6400. For example, in the case where a user operates the display device 6000, a signal may be output from the application processor 6200 for the purpose of driving the display panel 6600, and the output signal may be transferred to the DDI package 6400 through a printed circuit board (not shown). As an intermediate connector, the printed circuit board is an electronic part composed of circuits which may transfer electrical signals. According to an embodiment, a flexible printed circuit board may be used as the printed circuit board.
The DDI package 6400 may correspond to the electronic device 1000 of
Functions of the timing controller 6420 and the DDIs 6440 and an interface operation between the timing controller 6420 and the DDIs 6440 may be the same or similar to those described with reference to
As suggested by the illustration of
Accordingly, since the display device 6000 does not use a separate pad or a separate external element for the purpose of identifying a DDI to which a command will be transferred, it is possible to stably transfer a command through the shared channel SC being a low-speed bus.
According to one embodiment of the inventive concept, since the DDI package 6400 performs an interface operation with the timing controller 6420, the DDI package 6400 may include a graphic Random Access Memory (RAM, not shown) for temporarily storing data or a signal to be input to the DDIs 6440. Also, the DDI package 6400 may include a power source (not shown) which generates a voltage for driving the display panel 6600 and supplies the generated voltage to the DDIs 6440.
Referring to
In the case where the display device 6000 is a monitor and the communicating apparatus 7000 is a computer, an image may be displayed in a monitor based on data provided from storage of the computer. The storage may be used to store data information having various data forms such as a text form, a graphic form, and a software code form. For example, the storage may include an electrically erasable programmable read-only memory (EEPROM), a flash memory, a magnetic RAM (MRAM), a spin-transfer torque MRAM (STT-MRAM), a conductive bridging RAM (CBRAM), a ferroelectric RAM (FeRAM), a phase change RAM (PRAM) called a “ovonic unified memory (OUM)”, a resistive RAM (RRAM or ReRAM), a nanotube RRAM, a polymer RAM (PoRAM), a nano floating gate memory (NFGM), a holographic memory, a molecular electronics memory device, or an insulator resistance change memory.
The computer may include a CPU, a RAM, a user interface, a modem including a function of a baseband chipset, and a memory system. The CPU of the computer may be mounted in the form of a multi-processor. Also, the computer may further include an application chipset, a camera image processor (CIS), a mobile DRAM, etc.
In
Referring to
An electronic device according to an embodiment may use a signal on a data line being a high-speed channel for the purpose of selecting a DDI to which a command will be transferred, and the command may be transferred through a shared channel being a low-speed channel. Accordingly, the command may be stably transferred. Also, since a signal on a data line is used to select a DDI to which a command will be transferred, the electronic device does not require an additional pad or element for tagging identification information for the DDI.
While the inventive concept has been described with reference to exemplary embodiments thereof, it will be apparent to those of ordinary skill in the art that various changes and modifications may be made thereto without departing from the spirit and scope of the inventive concept as set forth in the following claims.
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