CN1293531C - Liquid crystal screen controlling method - Google Patents
Liquid crystal screen controlling method Download PDFInfo
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- CN1293531C CN1293531C CN 02100718 CN02100718A CN1293531C CN 1293531 C CN1293531 C CN 1293531C CN 02100718 CN02100718 CN 02100718 CN 02100718 A CN02100718 A CN 02100718A CN 1293531 C CN1293531 C CN 1293531C
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Abstract
The present invention relates to a method for controlling a liquid crystal screen. A display control signal and a data signal of an LCD are simulated and generated by a CPU of a PDA, and the display control signal and the data signal are output to the LCD to control the display of the LCD. the method for controlling a liquid crystal screen provided by the present invention has the advantage that a special hardware LCD controller is replaced by the LCD control signal output by the CPU existing in the PAD. thus, the cost of the hardware of an intelligent electronic product with an LCD is reduced; meanwhile, the operation controlling capability of the CPU is fully utilized, and the latent capacity of the CPU of the intelligent electronic product is displayed.
Description
Technical field:
The present invention relates to a kind of control method of LCDs, be meant a kind of especially at personal digital assistant (Personal Digital Assistant, be called for short PDA) in, with microprocessor and simple logic control circuit instead of dedicated LCDs control circuit, to reach the method that reduces LCDs control hardware cost purpose.
Background technology:
LCDs (Liquid Crystal Display is called for short LCD) is an indispensable display device on present many intelligent electronic products.Because LCD has plurality of advantages such as in light weight, that energy consumption is low, has been the display device of standard on such as PDA products such as palm PCs.
The controller of existing LCD (for example: STN type lcd controller) mainly adopt the lcd controller of ready-made embedded type CPU or the lcd controller of tyre, such processor or lcd controller all are the specific hardware products that is specifically designed to LCD control, and price is higher relatively; Influenced by this, reduce such as the cost of products of personal digital assistants such as palm PC is very difficult always.
Referring to Fig. 1, the controller of general LCD is made of 7 control modules such as Microprocessor Interface register, control logic circuit, screen direct memory access (DMA) (being called for short screen DMA), line style buffer (Line Buffer), cursor logical circuit, Frame-rate Control and LCD interfaces usually, by adopting the mode of DMA, produce the control signal wire of corresponding LCD.Because above-mentioned lcd controller adopts unique design, so its hardware cost is very high.
The CPU that is had in many intelligent electronic products (for example PDA etc.), beyond being used for calculating normally and running application, also have enough computings and control surplus, therefore only with regard to the control of LCD, can utilize CPU to come the hardware lcd controller of replace dedicated fully, and then reduce the hardware cost of product.
Summary of the invention:
Fundamental purpose of the present invention is to provide a kind of control method of LCDs, and it utilizes the CPU that has had in the intelligent electronic product, the hardware lcd controller of replace dedicated, and reduction has the hardware cost of the intelligent electronic product of LCD.
Another purpose of the present invention is to provide a kind of control method of LCDs, makes full use of computing, the control ability of CPU, the potentiality of performance intelligent electronic products C PU.
The object of the present invention is achieved like this:
A kind of control method of LCDs, the CPU simulation of PDA generates display control signal and the data-signal of LCD, and this display control signal and data-signal are outputed to LCD, the demonstration of control LCD; The CPU simulation of PDA generates the display control signal of LCD and the concrete grammar of data-signal is:
CPU utilizes counter to produce the line scanning IE signal of fixed cycle;
Produce each control signal in the interrupt service routine of being expert at;
With each control signal that is produced, utilize the input/output end port output of CPU.
Described display control signal comprises at least: LCD control frame signal, LCD point control signal, LCD alternating signal and the capable control signal of LCD.
Described capable interrupt service routine specifically comprises the steps:
Step 1: judging when whether last screen refreshes and finish, is execution in step 2 then; Otherwise execution in step 3;
Step 2: reset refresh address and restart and refresh; Execution in step 4;
Step 3: refresh next line;
Step 4: judging whether to carry out frame control, is that control frame signal then is set is execution in step 5 behind the effective status; Otherwise direct execution in step 5;
Step 5; Make the alternating signal upset, it is effective status that capable control signal is set, and after time-delay, it is disarmed state that capable control signal is set again, and the set-point control signal is an effective status simultaneously;
Step 6: move video data from the display buffer to explicit address, the set-point control signal is an effective status simultaneously
Step 7: judging whether to carry out frame control again, is that control frame signal then is set is to finish behind the disarmed state; Otherwise, directly finish.
Described point control signal is undertaken obtaining behind the exclusive disjunction by general input/output signal (Genreal Purpose Input andOutput is called for short GPIO) and written allowance signal (Write Enable is called for short WE).
The data-signal of described LCDs directly adopts the data-signal of CPU.
The control method of LCDs provided by the invention, the control signal of the CPU output LCD by having had among the PAD has substituted special hardware lcd controller, therefore, has reduced the hardware cost of the intelligent electronic product with LCD; Can make full use of simultaneously the s operation control ability of CPU, bring into play the potentiality of intelligent electronic products C PU.
Description of drawings:
Fig. 1 is the theory structure synoptic diagram of existing hardware lcd controller.
Fig. 2 is the sequential synoptic diagram of each control signal of LCD.
Fig. 3 is the connection diagram of CPU of the present invention and LCD.
Fig. 4 produces the process flow diagram of LCD control signal for the present invention.
Embodiment:
Referring to Fig. 2 and Fig. 3, within the one-period of LCD control frame signal LFRM, corresponding all row control signal LLP of this LCD, then corresponding all point control signal LCLK of this row in the one-period of each row control signal LLP; In the respective cycle of each point control signal LLP, CPU sends the display data signal D0-D3 of this point.Therefore, directly adopt the data-signal of the data-signal D0-D3 of CPU among the present invention as LCD; CPU adopts a counter to carry out timing, and when this rolling counters forward reached predefined time, then CPU began to produce the various control signals of LCD in the one-period, so repeated can realize exporting with CPU the control signal of various LCD.
Referring to Fig. 4, the concrete grammar of the various control signals of LCD is as follows in the CPU generation one-period:
Step 1: judging when whether last screen refreshes and finish, is execution in step 2 then; Otherwise execution in step 3;
Step 2: reset refresh address and restart and refresh; Execution in step 4;
Step 3: refresh next line;
Step 4: judging whether to carry out frame control, is that control frame signal LFRM then is set is execution in step 5 behind the effective status; Otherwise direct execution in step 5;
Step 5; Make alternating signal LACD upset, it is effective status that capable control signal LLP is set, and after time-delay, it is disarmed state that capable control signal LLP is set again, and set-point control signal LCLK is an effective status simultaneously;
Step 6: move video data from the display buffer to explicit address, set-point control signal LCLK is an effective status simultaneously;
Step 7: judging whether to carry out frame control again, is that control frame signal LFRM then is set, for finishing behind the disarmed state; Otherwise, directly finish.
The data-signal of LCD directly adopts the data-signal D0-D3 of CPU, in order in the application of reality, to distinguish the character of its data, can adopt WE and GPIO's or combination produce point control signal LCLK, be about to the WE signal of CPU and GPIO signal simultaneously through exporting to LCD as point control signal LCLK behind the exclusive disjunction.
By above mode, in the design palm PC, the embedded type CPU that can select for use some not have lcd controller because the CPU model of the type is general relatively older, therefore when satisfying actual demonstration control, can also reduce cost significantly.
It should be noted last that: above embodiment is the unrestricted technical scheme of the present invention in order to explanation only, although the present invention is had been described in detail with reference to the foregoing description, those of ordinary skill in the art is to be understood that: still can make amendment or be equal to replacement the present invention, and not breaking away from any modification or partial replacement of the spirit and scope of the present invention, it all should be encompassed in the middle of the claim scope of the present invention.
Claims (5)
1, a kind of control method of LCDs is characterized in that: the CPU simulation of PDA generates display control signal and the data-signal of LCD, and this display control signal and data-signal are outputed to LCD, the demonstration of control LCD; The CPU simulation of described PDA generates the display control signal of LCD and the concrete grammar of data-signal is:
CPU utilizes counter to produce the line scanning IE signal of fixed cycle;
Produce each control signal in the interrupt service routine of being expert at; With each control signal that is produced, utilize the input/output end port output of CPU.
2, the control method of LCDs according to claim 1 is characterized in that: described display control signal comprises at least: LCD control frame signal, LCD point control signal, LCD alternating signal and the capable control signal of LCD.
3, the control method of LCDs according to claim 1 is characterized in that: described capable interrupt service routine specifically comprises the steps:
Step 1: judging when whether last screen refreshes and finish, is execution in step 2 then; Otherwise execution in step 3;
Step 2: reset refresh address and restart and refresh; Execution in step 4;
Step 3: refresh next line;
Step 4: judging whether to carry out frame control, is that control frame signal then is set is execution in step 5 behind the effective status; Otherwise direct execution in step 5;
Step 5: make the alternating signal upset, it is effective status that capable control signal is set, and after time-delay, it is disarmed state that capable control signal is set again, and the set-point control signal is an effective status simultaneously;
Step 6: move video data from the display buffer to explicit address, the set-point control signal is an effective status simultaneously;
Step 7: judging whether to carry out frame control again, is that control frame signal then is set is to finish behind the disarmed state; Otherwise, directly finish.
4, the control method of LCDs according to claim 3 is characterized in that: described point control signal is undertaken obtaining behind the exclusive disjunction by GPIO signal and WE signal.
5, the control method of LCDs according to claim 1 is characterized in that: the data-signal of described LCDs directly adopts the data-signal of CPU.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 02100718 CN1293531C (en) | 2002-01-18 | 2002-01-18 | Liquid crystal screen controlling method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 02100718 CN1293531C (en) | 2002-01-18 | 2002-01-18 | Liquid crystal screen controlling method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1432986A CN1432986A (en) | 2003-07-30 |
| CN1293531C true CN1293531C (en) | 2007-01-03 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 02100718 Expired - Fee Related CN1293531C (en) | 2002-01-18 | 2002-01-18 | Liquid crystal screen controlling method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN1293531C (en) |
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2002
- 2002-01-18 CN CN 02100718 patent/CN1293531C/en not_active Expired - Fee Related
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| Publication number | Publication date |
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| CN1432986A (en) | 2003-07-30 |
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Owner name: LIANXIANG (BEIJING) CO. LTD.; HUMANTEC INDUSTRIAL Free format text: FORMER OWNER: LIANXIANG (BEIJING) CO. LTD. Effective date: 20080815 |
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Effective date of registration: 20080815 Address after: No. 6, Pioneer Road, Haidian District information industry base, Beijing, China: 100085 Co-patentee after: Lenovo Mobile Communication Technology Ltd. Patentee after: Lenovo (Beijing) Co., Ltd. Address before: No. 6, Pioneer Road, Haidian District information industry base, Beijing, China: 100085 Patentee before: Lenovo (Beijing) Co., Ltd. |
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| CF01 | Termination of patent right due to non-payment of annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20070103 Termination date: 20210118 |