LC7985NA Sanyo Semiconductor Corporation, LC7985NA Datasheet
LC7985NA
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LC7985NA Summary of contents
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... TOKYO OFFICE Tokyo Bldg., 1-10, 1 Chome, Ueno, Taito-ku, TOKYO, 110 JAPAN Package Dimensions unit: mm 3044B - QFP80A 7-pixel and 5 10-pixel unit: mm 3177 - QFP80D 10-pixel charac- 10-pixel char- 8-character and 2-line 8- 80-character or 2-line 40- CMOS LSI LC7985NA, LC7985ND LCD Controller/Driver [LC7985NA] [LC7985ND] 70197HA (ID) / N062JN No. 3255—1/30 ...
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... Pin Assignment Block Diagram LC7985NA, LC7985ND Top view No. 3255—2/30 ...
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... Parameter Supply voltage range *1 Supply voltage Input high level voltage Input low level voltage Note: *1. These voltages guarantee correct operation of the LC7985NA and LC7985ND. They do not guarantee correct operation of the LCD panel. V must also be observed. LCD Electrical Characteristics + ...
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... DD V off time DD Clock Generator The internal oscillator that generates the clock for the internal circuit requires an external filter, a feedback resistor or an external clock input as shown in the following sections. LC7985NA, LC7985ND Symbol Conditions f Ceramic filter oscillator OSC1 Feedback resistor oscillator, f ...
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... External clock The input duty cycle should be between 45 and 55% as shown in the following figure. Ceramic filter Note Feedback resistor Note. The resistor should be mounted as close as possible to OSCI and OSCO. Measurement Circuit LC7985NA, LC7985ND T h Note. Duty 100% = --------------- - 10 680pF 10 3.3k Note ...
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... Read/write cycle timing LC7930N interface timing Power supply LC7985NA, LC7985ND No. 3255—6/30 ...
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... DD, SS OSCI, OSCO 2 LC7985NA, LC7985ND Functions Data register or instruction register select input. Data register when "1" and instruction register when "0". Read or write select input “0” indicates write, “1” ; read Execution start input to write or read 4-bit microcontroller interface data bus and 8-bit microcontroller interface high-order four bits data bus connections. Three-state bidirectional. DB can be used as a busyfl ...
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... To prevent undesirable effects such as display flicker dur- ing DD RAM accesses, the internal memory and the microprocessor interface have separate timing signals. LC7985NA, LC7985ND The data register holds data read from or written to either DD RAM or CG RAM. Data written to the data register by the microcontroller is automatically transferred to the cur- rent DD RAM or CG RAM address ...
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... The DD RAM addresses following left and right display shifts are shown in the following figure. The number of displayed characters can be increased by adding more LC7930Ns. An LC7985 and nine LC7930Ns can drive an 80-character display as shown in the following figure. LC7985NA, LC7985ND No. 3255— ...
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... An LC7985 and a single LC7930N can drive a 2-line addresses for an unshifted, 2-line 16-character display are shown in the following figure. The DD RAM addresses following left and right display shifts are shown in the following figure. LC7985NA, LC7985ND 40-character display are shown in the 16-character display ...
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... The character generator RAM stores user-defined bitmaps for either eight, 5 characters. To display character patterns stored in CG RAM, write the character codes, shown in the leftmost column of the following figure RAM. LC7985NA, LC7985ND 7-pixel bitmaps and 32, 5 10-pixel bitmaps as shown in the following ...
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... Character cord and the character bitmap LC7985NA, LC7985ND No. 3255—12/30 ...
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... If the cursor is used, row 111 should contain all 0s so the cursor does not obscure the bottom row of the character. LC7985NA, LC7985ND 7-pixel characters is Bits the CG RAM data contain the character bit- maps. When a bit is 1, the corresponding pixel is ON, and when 0, the pixel is OFF ...
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... DD RAM, CG ROM and CG RAM are independent of the microcontroller interface so that memory accesses by the microcontroller do not cause interference with the display drive signals. LC7985NA, LC7985ND 10-pixel characters is contain all 0s so the cursor does not obscure the bottom row of the character. ...
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... Display ON/OFF instruc- tion. The cursor position is at the character corresponding to the address counter value as shown in the following fig- LC7985NA, LC7985ND The display bitmap data for each pixel-row is generated starting with the right-most character position. The data shifts through the shift register and is output on the shift register serial data output ...
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... LC7985 must be initialized using commands from the microcontroller. The initialization sequence is as follows. LC7985NA, LC7985ND status or instruction byte. The high-order four bits—bits DB4 to DB7 in 8-bit interface mode—are transferred first. The low-order four bits are then transferred as shown in the following fi ...
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... BF =1: internally operating Note: *1.The execution time depends on the operating frequency. For example LC7985NA, LC7985ND Data read and write instructions are usually the most fre- quently used instructions. For increased microcontroller efficiency, a display shift and display data write can be executed simultaneously ...
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... DD RAM or when data is read from or written to the CG RAM, although the address counter increments or decrements for all read and write operations. When display shift is OFF. LC7985NA, LC7985ND Display ON/OFF ), returns the Sets the display, the cursor and character blinking OFF ...
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... Outputs the busy flag state and the address counter value. The busy flag is used to check if the previous instruction has finished executing. When the previous instruc- LC7985NA, LC7985ND tion is executing, and when 0, the instruction has com- pleted. The next instruction cannot be received until The microcontroller should, therefore, confi ...
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... The busy flag and address counter value are Note. IR7 and IR3 are the 7th and 3rd bit, respectively, of the instruction. AC3 is the 3rd bit of the address counter. LC7985NA, LC7985ND output as two 4-bit words. Checking the busy flag, there- fore, requires two read cycles so the low-order four bits of the address counter value are fl ...
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... Sample Application Circuits 1-line 8-character, 1/4-bias and 1/8-duty Display with 5 1-line 8-character, 1/4-bias and 1/11-duty Display with 5 LC7985NA, LC7985ND Display lines Font size 5 7-pixel + 1 cursor 5 10-pixel + ...
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... Display with 5 7 pixel Font Alternative Display Connections The LC7985 to LCD panel connections can be varied to match the LCD panel matrix as shown in the following sections. 1-line 16-character, 1/8-bias and 1/16-duty Display with 5 7 pixel Font LC7985NA, LC7985ND 7-pixel Font No. 3255—22/30 ...
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... The voltages can be produced using a voltage-divider resistor network. The voltages required depend upon the duty cycle the LCD driver peak voltage, where LCD LCD DD 5 1/8 duty LCD drive LC7985NA, LC7985ND Voltage 1/4 bias and 1/8 or 1/11 duty ...
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... LCD drive 1/16 duty LCD drive LC7985NA, LC7985ND No. 3255—24/30 ...
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... When using a single-line display nine LC7930Ns, and when using a two-line display four LC7930Ns can interface to the LC7985 using the circuit shown in the following figure. The LC7985 LOAD, CP, M and D outputs con- nect directly to the LC7930Ns. Take care that the voltage reference outputs are connected correctly to the LC7930Ns. LC7985NA, LC7985ND No. 3255—25/30 ...
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... Cursor Home LC7985NA, LC7985ND Since the DD RAM stores 80 characters, the display shift function can be used as shown in the example. Note that display shifts only change the display position and do not alter the DD RAM. Using the Cursor Home instruction, therefore, returns the display to its original position. ...
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... DD Wait longer than 4.1ms Wait longer than 100 s Initialization complete LC7985NA, LC7985ND device, the LC7985 must be initialized using commands from the microcontroller. The busy flag cannot be tested before the Function Set instruction sets the interface size. The busy flag cannot be tested before the Function Set instruction sets the interface size. The busy fl ...
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... Cursor Home LC7985NA, LC7985ND time the display shifts, the characters in each row only move within the row. Note that if power supply conditions are such that the internalreset circuit does not operate to initialize the device, the LC7985 must be initialized using commands from the microcontroller ...
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... DD Wait longer than 4.1ms Wait longer than 100 s Initialization complete LC7985NA, LC7985ND DB0 to DB3 are not connected, however, and are not writ- ten. The Function Set instruction should therefore be repeated, writing DB4 to DB7 again and then DB0 to DB3, The busy flag cannot be tested before the Function Set instruction sets the interface size. The busy fl ...
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... This catalog provides information as of July, 1997. Specifications and information herein are subject to change without notice. LC7985NA, LC7985ND No. 3255—30/30 ...