NJU6535 Preliminary 1/3 , 1/4 Duty LCD Driver GENERAL DESCRIPTION The NJU6535 is a 1/3 or 1/4 duty LCD driver for segment type LCD panel with key scan function transmitting the 30 keys maximum scanned data (6 x 5 = 30) to CPU. The NJU6535 chooses numbers of common, key scan, and general purpose ports by instructions. Therefore, It drives 126 segments at 1/3 duty in use of 3 commons and 42 segments or 164 segments at 1/4 duty in use of 4 and 41. Also it provides 4 general purpose output ports maximum to drive LEDs or others directly. Furthermore, the NJU6535 can select a LCD driving voltage out of 8 steps voltage by the instruction to adjust the display contrast of LCD panel. PACKAGE OUTLINE NJU6535FG1 NJU6535FH1 FEATURES 42-segment Drivers Programmable Duty Ratio 1/3 Duty : 126-segment (Maximum) 1/4 Duty : 164-segment (Maximum) 30-key Scan Function (6X5 matrix) Needless for anti-reverse current diodes in key scan Programmable Bias Ratio 1/2, 1/3 bias Output Port for LED (maximum 4 LED) Serial Interface (SI, SO, SCL, CS) Useful Instruction set Incorporated LCD Driving Voltage Generator Circuits Electrical Variable Resistance (8-step) Logic Operating Voltage 4.5 ~ 5.5V LCD Driving Voltage ~5.5V Package Outline QFP64-G1 QFP64-H1 C-MOS Technology (Substrate :P) 02/08/06 -1- NJU6535 S4 S3 S2 SEG42/S1 SEG41/S0 SEG40/COM4 COM3 COM2 COM1 SEG39 SEG38 SEG37 SEG36 SEG35 SEG34 SEG33 PIN LOCATION SEG32 SEG31 SEG30 SEG29 SEG28 SEG27 SEG26 SEG25 SEG24 SEG23 SEG22 SEG21 SEG20 SEG19 SEG18 SEG17 SEG1/P0 SEG2/P1 SEG3/P2 SEG4/P3 COM3 COM2 COM1 BLOCK DIAGRAM SEG37 SEG38 SEG39 SEG40/COM4 SEG41/S0 SEG42/S1 SEG1/P0 SEG2/P1 SEG3/P2 SEG4/P3 SEG5 SEG6 SEG7 SEG8 SEG9 SEG10 SEG11 SEG12 SEG13 SEG14 SEG15 SEG16 S5 K0 K1 K2 K3 K4 VDD V0 V1 V2 VSS OSC SO CE SCL SI VDD Segment Driver Common Driver E.V.R. General output Driver V0 Instruction Data Buffer V1 V2 Display Data Buffer Instruction decoder VSS Oscillator Key Buffer VDD Reset Reset I/O Buffer Key Scan controller S2 S3 S4 S5 K0 K1 K2 K3 K4 SO SI SCL VSS CE OSC -2- NJU6535 TERMINAL DESCRIPTION 1 No. 1 2 3 4 5 to 39 I/O O FUNCTION LCD Segment output terminal / General output terminal. Select Segment output terminal or General output terminal by the instruction. O LCD Segment output terminal 40 41 42 43 SYMBOL SEG1/P0 SEG2/P1 SEG3/P2 SEG4/P3 SEG5 to SEG39 COM1 COM2 COM3 SEG40/COM4 O LCD Common output terminal O 44 45 SEG41/S0 SEG42/S1 O 46 47 48 49 50 to 54 S2 to S6 O LCD Segment output terminal / LCD Common output terminal SEG40 in 1/3Duty use, COM4 in 1/4Duty use. LCD Segment output terminals / key scanning output terminals Select Segment output terminal or key scanning output terminal by the instruction. (No need for anti-reverse current diode in key scan) Key scanning output terminals. (No need for anti-reverse current diode in key scan) K0 to K4 I 55 56 57 58 59 60 VDD V0 V1 V2 VSS OSC I I/O 61 62 63 64 SO CE SCL SI O I I I Key scanning input terminals. (with internal pull-down resistor) Power source: VDD=5V with LCD driving voltage input. LCD driving voltage stabilization capacitor terminals. In use of 1/2 bias, connects V1 to V2. GND: VSS=0V System clock input terminal This terminal should be open for internal clock operation. Change Oscillation frequency by connecting capacitor and resistor. Inputs external oscillation clock. Data output terminal. Chip enable terminal. Shift clock input terminal. Data input terminal. -3- NJU6535 FUNCTIONAL DESCRIPTION (1) Description for each blocks (1-1) Serial I/F The Serial I/F controls serial data from external data. (1-2) Instruction Reg. The Instruction Register stores instruction code from external. (1-3) Instruction Decoder. The instruction decoder decodes instruction code and controls each blocks (1-4) Data Buffer for Display. The Data Buffer for Display stores data for display from external. (1-5) Segment Driver / General output Driver. The Segment Driver generates driving waveform to Segment terminal on Display data. The General output Driver generates “H” or “L” level to General output terminal on output data. (1-6) Common Driver. The Common Driver generates driving waveform to Common terminal . (1-7) Electrical Variable Resistance (E.V.R.) The Electrical Variable Resistance adjusts LCD Driving Voltage from V0 to V2. (1-8) Key Scan Controller. The Key Scan Controller controls to input from external KEY data. (1-9) Data buffer for Key. The Data buffer for key stores Key Data until next key data is stored. (1-10) CR Oscillator The Oscillator is CR oscillator which generates the master clock. (1-11) Reset Circuit The Reset circuit is type of detectable voltage. It resets internal circuit when the power turns on or drop the voltage. The Reset circuit is initializes the NJU6535 at Power ON and OFF. It generates reset signal to initialize the system at low VDD less than power down detection voltage (2.5V typical). -4- NJU6535 INSTRUCTIONS The instruction code is consisted of 12-bits data and inputs with display data. (see “Table 1 Instruction Code). Table 1. DY E0 E1 E2 Instruction Instruction Code S0 S1 Duty Select Symbol DY EVR Register Set E0-E2 Power Save mode set S0-S1 Segment output / Key scan output selection K0, K1 Segment output / General output port selection P0, P1 Display ON / OFF SC Bias selection DR K0 K1 P0 P1 SC DR Description Set the 1/3duty or 1/4duty. 0: 1/3 Duty 1: 1/4 Duty Set the contraction for 000 – 111 (8-voltage conditions) 00: Normal 01: Power save 1 10: Power save 2 11: Power save 3 00: 30 keys 01: 25 keys 1x: 20 keys “x” is Don’t care 00: 4 segment outputs 01: 2 General output ports 10: 3 General output ports 11: 4 General output ports 0: Display ON 1: Display OFF 0: 1/3 bias 1: 1/2 bias (connect V1 to V2 terminal) -5- NJU6535 (2) INSTRUCTIONS CODE (2-1) Duty select Duty select instruction is which sets LCD driving duty ratio 1/3 or 1/4 duty. No.43 terminal is change Common terminal or segment terminal shown below. Table 1 DY Duty ratio 0 1 1/3 Duty 1/4 Duty No.40 COM1 COM1 No.40 to 43 terminal states No.41 No.42 COM2 COM3 COM2 COM3 No.43 SEG40 COM4 (2-2) E.V.R. resister set E.V.R. resister set instruction adjusts the contrast of the LCD, and selects. One LCD driving voltage VLCD out of 8 voltage-stages by setting E.V.R. register. Set the binary code “000” when contrast adjustment is unused. VLCD E0 E1 E2 VLCD (VLCD=V0-VSS) 1/2 bias 1/3 bias 0 0 0 VDD VDD High 0 0 1 0.933VDD 0.955VDD : 0 1 0 0.875VDD 0.913VDD : 0 1 1 0.824VDD 0.875VDD : 1 0 0 0.778VDD 0.840VDD : 1 0 1 0.737VDD 0.808VDD : 1 1 0 0.700VDD 0.778VDD : 1 1 1 0.667VDD 0.750VDD Low (2-3) Power save mode set Power save mode reduces the operating current of application using Display Off and selects a terminal condition of Key scan signal output. The terminal, which is set to "L", does not output Key scan signal as shown in following table. S0 S1 Function 0 0 Normal 0 1 Power save 1 1 0 Power save 2 1 1 Power save 3 *1 No scanning states. Key scanning output terminals Internal OSC. LCD output ON Stop Stop Stop ON Display Off Display Off Display Off S0 H L L H S1 H L L H states *1 S2 S3 H H L L L L H H S4 H L H H S5 H H H H (2-4) Segment output / key scan output selection This instruction assigns a function of output terminal either segment output or Key scan signal output to 5 terminals numbered from 44 to 45 as shown in following table. No.44 to 49 terminal states Maximum key K0 K1 matrix No.44 No.45 No.46 No.47 No.48 No.49 S0 S1 S2 S3 S4 S5 0 0 30 key SEG41 S1 S2 S3 S4 S5 0 1 25 key SEG41 SEG42 S2 S3 S4 S5 1 * 20 key (*:Don’t care) -6- NJU6535 (2-5) Segment output / General output port selection This instruction assigns function of output terminal either segment output or general purpose output port to 4 terminals numbered from 1 to 4 as shown in following table. No.1 to 4 terminal states General P0 P1 output ports No.1 No.2 No.3 No.4 0 0 0 port SEG1 SEG2 SEG3 SEG4 0 1 2 ports P0 P1 SEG3 SEG4 1 0 3 ports P0 P1 P2 SEG4 1 1 4 ports P0 P1 P2 P3 (2-6) Display ON / OFF Display ON / OFF instruction controls the whole Display On / Off. SC Function 0 Display On. Display Off. 1 All segment drivers output OFF waveform. Common waveform does not change. (2-7) Bias selection This instruction selects a LCD driving bias either 1/3 bias or 1/4 as shown in following table. DR Function 1/3 bias select 0 1/2 bias select (Connect V1 to V2 terminal) 1 -7- NJU6535 (3) Display data and output pin correspondence (3-1) 1/3Duty Output COM1 COM2 COM3 terminal SEG1 D1 D2 D3 SEG2 D4 D5 D6 SEG3 D7 D8 D9 SEG4 D10 D11 D12 SEG5 D13 D14 D15 SEG6 D16 D17 D18 SEG7 D19 D20 D21 SEG8 D22 D23 D24 SEG9 D25 D26 D27 SEG10 D28 D29 D30 SEG11 D31 D32 D33 SEG12 D34 D35 D36 SEG13 D37 D38 D39 SEG14 D40 D41 D42 SEG15 D43 D44 D45 SEG16 D46 D47 D48 SEG17 D49 D50 D51 SEG18 D52 D53 D54 SEG19 D55 D56 D57 SEG20 D58 D59 D60 SEG21 D61 D62 D63 Output terminal SEG22 SEG23 SEG24 SEG25 SEG26 SEG27 SEG28 SEG29 SEG30 SEG31 SEG32 SEG33 SEG34 SEG35 SEG36 SEG37 SEG38 SEG39 SEG40 SEG41 SEG42 COM1 COM2 COM3 D64 D67 D70 D73 D76 D79 D82 D85 D88 D91 D94 D97 D100 D103 D106 D109 D112 D115 D118 D121 D124 D65 D68 D71 D74 D77 D80 D83 D86 D89 D92 D95 D98 D101 D104 D107 D110 D113 D116 D119 D122 D125 D66 D69 D72 D75 D78 D81 D84 D87 D90 D93 D96 D99 D102 D105 D108 D111 D114 D117 D120 D123 D126 When selected, following data are assigned. Output Data terminal P0 D1 P1 D4 P2 D7 P3 D10 -8- NJU6535 (3-2) 1/4Duty Output terminal COM1 COM2 COM3 SEG1 D1 D2 SEG2 D5 D6 SEG3 D9 D10 SEG4 D13 D14 SEG5 D17 D18 SEG6 D21 D22 SEG7 D25 D26 SEG8 D29 D30 SEG9 D33 D34 SEG10 D37 D38 SEG11 D41 D42 SEG12 D45 D46 SEG13 D49 D50 SEG14 D53 D54 SEG15 D57 D58 SEG16 D61 D62 SEG17 D65 D66 SEG18 D69 D70 SEG19 D73 D74 SEG20 D77 D78 SEG21 D81 D82 Note) SEG40 is changed to COM4 D3 D7 D11 D15 D19 D23 D27 D31 D35 D39 D43 D47 D51 D55 D59 D63 D67 D71 D75 D79 D83 COM4 D4 D8 D12 D16 D20 D24 D28 D32 D36 D40 D44 D48 D52 D56 D60 D64 D68 D72 D76 D80 D84 Output terminal COM1 COM2 COM3 COM SEG22 SEG23 SEG24 SEG25 SEG26 SEG27 SEG28 SEG29 SEG30 SEG31 SEG32 SEG33 SEG34 SEG35 SEG36 SEG37 SEG38 SEG39 SEG41 SEG42 D85 D89 D93 D97 D101 D105 D109 D113 D117 D121 D125 D129 D133 D137 D141 D145 D149 D153 D157 D161 D86 D90 D94 D98 D102 D106 D110 D114 D118 D122 D126 D130 D134 D138 D142 D146 D150 D154 D158 D162 D87 D91 D95 D99 D103 D107 D111 D115 D119 D123 D127 D131 D135 D139 D143 D147 D151 D155 D159 D163 D88 D92 D96 D100 D104 D108 D112 D116 D120 D124 D128 D132 D136 D140 D144 D148 D152 D156 D160 D164 When selected, following data are assigned. Output terminal Data P0 P1 P2 P3 D1 D5 D9 D13 (3-3) Display data and segment status Display data Segment “H” On “L” Off -9- NJU6535 (4) Input Data Format and Timing Data format is shown below. When the CE terminal goes to “H” (rising edge) at SCL terminal “H”, I/F is data input. (4-1) 1/3Duty Data 1 (D1 to D42 and Instruction) CE SCL SI D1 D2 D42 DY E0 E1 E2 S0 S1 K0 K1 P0 P1 SC DR 0 Display Data Instruction 0 Discernment data Data 2 (D43 to D84) CE SCL SI D84 * D43D44 * Display Data * * * * * * * * * * Dummy data (Don’t Care) 12 0 1 Discernment data SO Data 3 (D85 to D126) CE SCL SI D85 D86 Display Data D126 * * * * * * * * * * Dummy data (Don’t Care) 12 * * 1 0 Discernment data SO NOTE1) All of display data should be transmitted within 30 mS to keep the display quality, because huge display data D1 to D126 are transmitted at 3 times totally. NOTE2) Data fetched at SCL rising edge. NOTE3) Data executed at CE falling edge. NOTE4) In case of entering less then 56-bit data, invalid data. NOTE5) In case of entering over then 56-bit data, valid data is last 56-bit data. - 10 - NJU6535 (4-2) 1/4Duty Data 1 (D1 to D44 and Instruction) CE SCL SI D1 D2 D42 D43 D44 DY E0 E1 E2 S0 S1 K0 K1 P0 P1 SC DR Display data Instruction 0 0 Discernment data SO Data 2 (D45 to D84) CE SCL D45 D46 SI D84 * * * * * * Display data * * * * * * * * * Dummy data (Don’t Care) 16 * 0 1 Discernment data SO Data 3 (D85 to D124) CE SCL D85 D86 SI D124 * * * * Display data * * * * * * * * * * * Dummy data (Don’t Care) 16 * 1 0 Discernment data SO Data 4 (D125 to D164) CE SCL D125 D126 SI Display data D164 * * * * * * * * * * * * Dummy data (Don’t Care) 16 * * * * 1 1 Discernment data SO NOTE1) All of display data should be transmitted within 30 mS to keep the display quality, because huge display data D1 to D164 are transmitted at 4 times totally. NOTE2) Data fetched at SCL rising edge. NOTE3) Data executed at CE falling edge. NOTE4) In case of entering less then 58-bit data, invalid data. NOTE5) In case of entering over then 58-bit data, valid data is last 58-bit data. NOTE5) Power is turn on time, set the 1/4Duty mode. - 11 - NJU6535 (5) Power save mode Power save mode 1 to 3 is set by “1” level as a control data in PS0 or 1, and released by “0” in PS0 and PS1. In power save mode, segment drivers and commons output “L” level and the internal oscillation circuit is stop the operation ( but operates at Key in detection) for operation current reduction. However, output terminals SEG1/P0 to SEG4/P3 operate as General output port set by control data P0 and P1 in power save mode. (refer (1)Instruction (e)Segment output / General output port) (6) Key scan circuit Key scan circuit connects the 6 x 5 key-matrix maximum and reads the data of 30 keys maximum. It chooses the number of keys in key-matrix by “Segment output / key scan output select” instruction. It outputs a identified key data to CPU after comparison with two data read from the key-matrix in twice for reliable key operation. If those data are not identified, key data is not outputted. It outputs “L” signal through “SO” terminal as the request after 577T[s] (T=1/fosc) when any key is operated. Furthermore, the key scan circuit structures for reducing the external components like as Diodes to prevent circuit short problem. (6-1) The relation between output data and key matrix The relation between output data and key matrix shows bellow table and sets “1” signal for operated key. In case of 20 keys application, unassigned area for keys from KD1 to KD10 in bellow table take “0” signal. In case of 25 keys application, unassigned area from KD1 to KD5 take “0” signal also. In mode of Power save 1, area for keys from KD1 to KD25 in bellow table take “0” signal. In mode of Power save 2, area from KD1 to KD20 take “0” signal also. The terminals, which are not connected any keys, should be open. K0 K1 K2 K3 K4 S0 KD1 KD2 KD3 KD4 KD5 S1 KD6 KD7 KD8 KD9 KD10 S2 KD11 KD12 KD13 KD14 KD15 S3 KD16 KD17 KD18 KD19 KD20 S4 KD21 KD22 KD23 KD24 KD25 S5 KD26 KD27 KD28 KD29 KD30 (6-2) Data output timing The data output format shows bellow. The data output mode is set by “L” status of SCL terminal at the rising signal of CE terminal. CE SCL SI SO * KD1 KD2 KD29 KD30 PSF Key data (6-3) Power save flag(PSF) The status of Power save flag is outputted after KD30 in Key data reading. This flag sets “1” signal in mode of Power save in Key data reading and sets “0” in mode of Normal. - 12 - NJU6535 (6-4) Timing of Key scan Key scan cycle is 288T[S]. The data of key scan is a result of comparison with a couple of Key scan for correct judge whether Key On or Off. When the result of comparison is correct (accord), the NJU6535 recognizes Key On and outputs “L” level from SO terminal after 577T[S] from start of Key scan for a request to read key data out to external CPU. When the SO terminals outputs “L” signal, the key scan does not operate until end of key data reading by CPU, and scanned key data is kept. When the result of comparison is incorrect (not accord), Key scan operates again if any key is On. Therefore, Key scan may operate incorrectly in case of shorter period of Key on than 577T[S] Key ON 288T[s] S0 *1 S1 *1 S2 *1 S3 *1 S4 *1 S5 1 1 2 *1 2 3 *1 3 4 *1 4 5 *1 5 6 *1 6 T = 1 / fosc SO 577T [s] *1 Instruction data K0, K1 set the output ports to output the scan signals (refer (1)Instruction (2-4)Segment output / Key scan selection) Key scan cycle and the timing of Key data read out request are constant in any combination of S0, S1, K0 and K1. - 13 - NJU6535 (6-5) Normal mode Key scan operates with follows in normal mode. 1, Key scan signal output terminals S0 – S5 output “H” signals when key scan does not operate, and output key scan signals after start of key scan operation. The conditions of key scan signal input terminals K0 – K4 are “L” state with internal pull-down resistances, though “H” signal comes in to K0 – K4 corresponding to the turned on keys. 2, The function of key scan starts twice operations when any key is turned on. It stops when a couple of data by continuously twice key scan operations are accorded and fixed as a correct key status. It operates more 2 times when the key status is not fixed and any keys are still turning on. It repeats again and again until key status is fixed. The correct key status data is stored and newly key scan operation does not start until external CPU reads data out after key status is fixed. 3, When the key status is fixed, SO terminal outputs “L” signal as Key data read out request to CPU. CPU should read key data out at detection of this “L” signal. If CPU writes the display data or instructions to the NJU6535 when SO terminal outputs “L” signal, SO terminal outputs “H” level during “CE” terminal is ”H”. 4, The Key data read out request signal is released and SO terminal outputs “H” signal after finish of CPU key data read out for newly key scan operation. SO terminal requires pull up resistor (1 Kohm to 10 Kohms) because of Open drain type output. Multiple data of key are output in case of key more input so that CPU should process the data by itself. Key scan example (Normal mode) T = 1 / fosc Key input 1 Key input 2 Key scan 577T[s] 577T[s] 577T[s] CE SCL Data send Data send Data send SI SO Key data read Key data read request Key data read Key data read request Key data read Key data read request - 14 - NJU6535 (6-6) Power save mode Key scan operates with follows in Power save mode. 1, Key scan signal output terminals S0 – S5 output “H”, “L” signals by the control data S0 and S1 when key scan does not operate (refer the detail of instructions), and output key scan signals after start of key scan operation. The conditions of key scan signal input terminals K0 – K4 are “L” state with internal pull-down resistances, though “H” signal comes in to K0 – K4 corresponding to the turned on keys. 2, The oscillation circuit function of key scan starts twice operations when any keys on cross points with S0– S5 terminals line and K0 – Ki turned on. It stops when a couple of data by continuously twice key scan operations are accorded and fixed as a correct key status. It operates more 2 times when the key status is not fixed and any keys are still turning on. It repeats again and again until key status is fixed. The correct key status data is stored and newly key scan operation does not start until external CPU reads data out after key status is fixed. 3, When the key status is fixed, SO terminal outputs “L” signal as Key data read out request to CPU. CPU should read key data out at detection of this “L” signal. If CPU writes the display data or instructions to the NJU6535 when SO terminal outputs “L” signal, SO terminal outputs “H” level during “CE” terminal is ”H”. 4, The Key data read out request signal is released and SO terminal outputs “H” signal after finish of CPU key data read out for newly key scan operation. Although Power save mode is not released. SO terminal requires pull up resistor (1Kohm to 10Kohms) because of Open drain type output. Multiple data of key are output in case of key more input so that CPU should process the data by itself. Key scan example (Power save mode) Ex.) PS0= ”0”, PS1= ”1” (K4=“H” power save) S0 “L” S1 “L” S2 “L” S3 “L” S4 “L” When some key on these lines are turned on, the oscillation starts and Key scan starts the operation until all of key are turned off. *1 S5 “H” K0 K1 K2 K3 K4 *1 These diodes are required to recognize key more input of keys on the K4 line when only K4 terminal outputs “H” signal in power save mode as shown above example. In case of no diodes, incorrect key data may read out sometimes by key more input of keys on lines of K0 to K4. Key input (K4) Key scan 577T[s] 577T[s] CE SCL Data send Data send Data send T = 1 / fosc SI SO Key data read Key data read request Key data read Key data read request - 15 - NJU6535 (6-7) Key More Input Key scan signal output terminal S0 to S5 output “H” level in state of Key More Input. Although Key state is detected without diodes to prevent unexpected key scan signal flow, non-pressed key data may change pressed key data in triple or more key Input as shown in Fig. 1 and incorrect key data may be output to external CPU. For prevention of miss-recognition by incorrect key data, diodes should be inserted in front of K0 – K4 terminals as shown in Fig. 3 or control program of CPU should ignore the combination of key data miss-recognition. For example, 4 keys and more ON data should be ignored. S0 Pressed key S1 Miss-recognized key S2 S3 In case of 3 keys operation in left picture, if S4 terminal outputs “H” signal, this signal goes around on the dotted line and non-pressed key is miss-recognized as pressed key. S4 S5 K0 K1 K2 K3 K4 Fig. 1 Miss-recognized example by key more input In modes of power save 1 (S0=0, S1=1 / Keys on only S5 line are valid) or power save 2 (S0=0, S1=1 / Keys on only S4 and S5 lines are valid), pay attention about the followings. When Key More Input is operated across the valid line and invalid, non-pressed key is miss-recognized as pressed key. However, Key data on the invalid line is not read out and 4 keys and more operation in the mean time are not ignored by CPU control program as shown in Fig. 2. In this case, diodes operate to prevent miss-recognition as shown in Fig. 3. S0 S0 S1 S1 S2 No active key S2 S3 S3 S4 S4 S5 Miss-recognition prevent diodes Active key K0 S5 K1 K0 K2 K3 K4 Pressed key Miss-recognized key In case of power save 1, CPU control program can not decide ether correct key data or incorrect as shown above because key data on only S4 line is read out to CPU (all of key data on S4 line become to “0” Fig. 2 Miss-recognition in power save 1 K1 K2 K3 K4 Fig. 3 Connect miss-recognition prevent diodes - 16 - NJU6535 (6-8) Key data reading out operation by external CPU (a) Display data writing Display data and instruction change operate at the rising edge of signal into CE terminal. Written data or instructions do not operate during CE terminal “H”. When the time to write whole display data into Data Buffer becomes too long by huge display data, display may be effected unexpected display. Data writing order from Data 1 to Data 3 in 1/3 duty or Data 1 to Data 4 in 1/4 duty is not limited. The duty is 1/3 after initialization. For 1/4 duty operation, Data 1 must be written first after initialization (b) Key data reading out operation The minimum period from Key in to SO terminal = “L” is 577T(t1) by key scan operation. When key scan operation performs again for key data fix preventing from noise or bouncing of key, the period from Key in to SO terminal = “L” is 1200T(t1). When the SO terminal outputs “L”, the key scan operation is stopped after execution of key data reading out operation. Therefore, fixed key data is kept until end of key data reading out operation. When key data reading out operation is performed during SO terminal = “H”, both of key data from KD1 to KD30 and power save flag (PSF) are not outputted correctly. Key data reading out operation example The flowchart below shows an example of timer interrupt application. When SO terminal condition is “L” after check of SO terminal condition at every timer interrupt operation, it is decided as Key In and key data reading out operation is performed. When SO terminal condition is “H, it is decided as Key Off. For the correct decision of Key Off, the timer interrupt cycle (1/t3) should be expanded over the time added with [period of key scan (1200T in case of measure against key bouncing of key) and [period of key data reading out operation (t2)]. In this time, the period of timer interrupt cycle (t3) must be set with enough margin including the range of fosc. Sequence of key data reading out operation Timer Yes SO=”L”? Key ON No Key OFF Key data read out End of Timer - 17 - NJU6535 Timing chart of key data reading out operation Key ON Key OFF Key input t1 t2 t1 t2 t1 SO CE SCL t3 t3 t3 t3 Interrupt Decision Key OFF Key ON Key OFF t1: Key scan time t2: Key data read time t3: Interrupt cycle *: t3 > t1 + t2 - 18 - NJU6535 (7) Power on reset circuit initializes Power on reset circuit initializes the NJU6535 at Power ON and OFF. It generates reset signal to initialize the system at low VDD less than power down detection voltage (2.5V typical). (7-1) Initial status in reset 1, Stop the oscillation circuit 2, Display Off (Available Serial data transmission) 3, Disable Key scan function 4, Filled “L”” data in all of key data buffer (7-2) The status of output port terminals in power on reset Output terminals SEG1/P0 to SEG4/P3 SEG5 to SEG39 SEG40/COM4 COM1 to COM3 S0/SEG41,S1/SEG42 S2 to S4 S5 SO *1 *2 *3 Reset status L *1 L L *1 L L *1 X *2 H H *3 This terminal operates as segment driver and outputs “L”. This terminal is not fixed the function in/after power on reset until PS0 and PS1 of control data are transmitted. This terminal consisted of Open-drain output type circuit requires external pull-up resister (1K ohm to 10k) connect ting to external power source for CPU. I f key data read is executed in power on reset, the read data is fixed as “H”. (7-3) Power on reset operation When the voltage rising time of power source is over than 1mS, the generated signal of VDET initializes the system of NJU6535 as reset. When the voltage falling time of power source is over than 1mS, the system is also reset. This status of reset is released automatically at the falling signal of CE terminal after completed serial data transmission ( Display data D1 to D126 and control data at 1/3 duty, Display data D1 to D164 and control data at 1/4 duty). t1 VDD t2 VDET VDET VDD rising time VDD falling time t1>1[ms] t2>1[ms] CE Internal data Display control data send Not fixed Fixed System reset time When these voltage rising or falling time of power source are not over than 1ms, the Initialization operaiton as reset does not operate correctly. - 19 - NJU6535 (8) LCD panel drive (8-1) LCD driving voltage generation circuit LCD driving voltage generation circuit generates LCD driving bias voltages V0, V1 and V2. It adjusts the voltage by 8 steps electrical volume from VDD and allots the voltage to V0, V1 and V2 by resistor-voltage-dividing as shown in below. VDD, V0, V1 and V2 terminals requires external capacitors for bias voltage stabilization for display quality. These values of capacitors should be fixed in accordance with evaluation in the application. NJU6535 internal VDD E.V.R.(8 steps) 10k V0 10k V1 10k V2 + + + VLCD + 10k VSS When the E.V.R. is not used, V0 terminal should connect to VDD. When the NJU6535 operates as 1/2 bias operation, V1 terminal should connect to V2. - 20 - NJU6535 Ta=25°°C ABSOLUTE MAXIMUMN RATINGS PARAMETER SYMBOL Supply Voltage VDDmax Input Voltage VI Output Voltage VO Power Dissipation Storage Temperature Operating temperature Pdmax Tstg Topr CONDITION RATINGS UNIT -0.3 to +6.0 V OSC, K0 to K4, V0 to V2 , CE, SCL, SI terminal, Ta=25°C -0.3 to VDD+0.3 V SO, OSC, SEG1 to SEG42,, COM1 to COM4, S0 to S5, P0 to P3 ,Ta=25°C -0.3 to VDD+0.3 V 300 -55 to +125 -40 to +85 mW VDD terminal, Ta=25°C Ta=85°C - °C °C Note1) All voltage values are specified as Vss = 0V. Note2) If the LSI are used on condition beyond the absolute maximum rating, the LSI may be destroyed. Using LSI within electrical characteristics is strongly recommended for normal operation. Use beyond the electric characteristics conditions will cause malfunction and poor reliability. Note3) Decoupling capacitor should be connected between VDD and Vss due to the stabilized operation for the voltage converter. - 21 - NJU6535 ELECTRICAL CARACTERISTICS VDD=5V+10%, Ta= - 40 to 85°C DC Characteristics PARAMETER SYMBOL Power supply VDD ”H” level input voltage(1) VIH(1) K0 to K4 ”H” level input voltage(2) VIH(2) SCL, SI, CE ”L” level input voltage(1) VIL(1) K0 to K4, SCL, SI, CE Hysteresis voltage VH ”H” level input current I IH ”L” level input current I IL Pull-down resistance RPD ”H” level output voltage(1) VOH(1) ”H” level output voltage(2) VOH(2) ”H” level output voltage(3) VOH(3) ”H” level output voltage(4) VOH(4) ”L” level output voltage(1) VOL(1) ”L” level output voltage(2) VOL(2) ”L” level output voltage(3) VOL(3) ”L” level output voltage(4) VOL(4) ”L” level output voltage(5) VOL(5) 1 VMC /2 1 VMC /3 2 VMC /3 1 VMS /3 SEG /3 level voltage 2 VMS /3 Oscillator Frequency Bleeder Resistance E.V.R. Resistance Power down detect voltage fosc RB REVR COM /2 level voltage COM /3 level voltage COM /3 level voltage SEG /3 level voltage 1 1 2 1 2 IDD2 IDD3 MIN TYP MAX UNIT 4.5 5.0 5.5 V 0.6VDD VDD V 0.8VDD VDD V 0 0.2VDD V SCL, SI, CE SCL, SI, CE VI = VDD SCL, SI, K0 to K4, CE VI = 0V K0 to K4 VDD=5.0V S0 to S5 Io = -500uA P1 to P4 Io = -10mA SEG1 to SEG42 Io = -20uA COM1 to COM4 Io = -100uA S0 to S5 Io = 25uA P1 to P4 Io = 10mA SEG1 to SEG42 Io = 20uA COM1 to COM4 Io = 100uA SO 0.3 COM1 to COM4 Io =+100uA COM1 to COM4 Io =+100uA COM1 to COM4 Io =+100uA SEG1 to SEG42 Io =+20uA SEG1 to SEG42 Io =+20uA Ta=25°C 0.25VDD -5.0 uA uA 50 100 250 kΩ VDD-1.2 VDD-0.5 VDD-0.2 V VDD-1.0 V V0-1.0 V V0-1.0 V 0.2 0.5 0.1 1.5 V 1.0 V 1.0 V 1.0 V 0.5 V 1 /2V0-1.0 1 /2V0+1.0 V 1 /3V0-1.0 1 /3V0+1.0 V 2 /3V0-1.0 2 /3V0+1.0 V 1 /3V0-1.0 1 /3V0+1.0 V 2 /3V0-1.0 2 /3V0+1.0 V 38 30 10 51 KHz 2.5 3.3 V 100 uA 250 500 uA 200 400 uA 25 Between V0-VSS, Ta=25°C Between VDD-V0, Ta=25°C 1.7 Power save mode VDD=5.5V, 1/2 Bias, Output terminal open VDD=5.5V, 1/3 Bias, Output terminal open V 5.0 Io = 1mA VDET IDD1 Operating Current CONDITION kΩ kΩ - 22 - NJU6535 VDD=5V+10%, Ta= - 40 to 85°C AC Characteristics PARAMETER “L” level clock pulse width “H” level clock pulse width CONDITION SYMBOL tWCLL tWCLH MIN SCL SCL TYP MAX UNIT 160 ns 160 ns Data setup time tDS SCL, SI / SO 160 ns Data hold time tDH SCL, SI / SO 160 ns CE wait time tCP CE, SCL 160 ns CE setup time tCS CE, SCL 160 ns CE hold time tCH CE, SCL 160 ns CE ”L” level width tWCL CE 160 ns SO output delay time tDC SO rise time tDR SCL rise time SCL fall time SO, Rpu=4.7 kΩ, CL=10pF SO, Rpu=4.7kΩ, CL=10pF 1.5 ms 1.5 ms tr 160 ns tf 160 ns SO terminal is Open-Drain type output, so that the characteristics of SO terminal are changed by values of pull-up resistance Rpu and CL. (1) Write operation CE tWCLL tWCLH tCH tWCL SCL tCP tCS SI tf D0 tr D1 tDS tDH tCP tCS tWCLH tWCLL SO (2) Key data read operation CE tCH SCL tr tf SI tDC SO tDR D0 - 23 - NJU6535 LCD DRIVING WAVEFORM (1) 1/3 Duty, 1/2 Bias Driving fosc/384(Hz) COM1 V0 V1,V2 VSS COM2 V0 V1,V2 VSS COM3 V0 V1,V2 VSS “OFF” segment output correspond to COM1, COM2 and COM3 V0 V1,V2 VSS “ON” segment output correspond to COM1 V0 V1,V2 VSS “ON” segment output correspond to COM2 V0 V1,V2 VSS “ON” segment output correspond to COM1 and COM2 V0 V1,V2 VSS “ON” segment output correspond to COM3 V0 V1,V2 VSS “ON” segment output correspond to COM1 and COM3 V0 V1,V2 VSS “ON” segment output correspond to COM2 and COM3 V0 V1,V2 VSS “ON” segment output correspond to COM1, COM2 and COM3 V0 V1,V2 VSS - 24 - NJU6535 (2) 1/3 Duty, 1/3 Bias Driving fosc/384(Hz) COM1 V0 V1 V2 VSS COM2 V0 V1 V2 VSS COM3 V0 V1 V2 VSS “OFF” segment output correspond to COM1, COM2 and COM3 V0 V1 V2 VSS “ON” segment output correspond to COM1 V0 V1 V2 VSS “ON” segment output correspond to COM2 “ON” segment output correspond to COM1, and COM2 “ON” segment output correspond to COM3 “ON” segment output correspond to COM1, and COM3 “ON” segment output correspond to COM2, and COM3 “ON” segment output correspond to COM1, COM2 and COM3 V0 V1 V2 VSS V0 V1 V2 VSS V0 V1 V2 VSS V0 V1 V2 VSS V0 V1 V2 VSS V0 V1 V2 VSS - 25 - NJU6535 (3) 1/4 Duty, 1/2 Bias Driving fosc/384(Hz) COM1 V0 V1,V2 VSS COM2 V0 V1,V2 VSS COM3 V0 V1,V2 VSS COM4 V0 V1,V2 VSS “OFF” segment output correspond to COM1, COM2, COM3 and COM4 V0 V1,V2 VSS “ON” segment output correspond to COM1 “ON” segment output correspond to COM2 “ON” segment output correspond to COM1 and COM2 “ON” segment output correspond to COM3 “ON” segment output correspond to COM1 and COM3 “ON” segment output correspond to COM2 and COM3 “ON” segment output correspond to COM1, COM2 and COM3 “ON” segment output correspond to COM4 “ON” segment output correspond to COM2 and COM4 “ON” segment output correspond to COM1, COM2, COM3 and COM4 V0 V1,V2 VSS V0 V1,V2 VSS V0 V1,V2 VSS V0 V1,V2 VSS V0 V1,V2 VSS V0 V1,V2 VSS V0 V1,V2 VSS V0 V1,V2 VSS V0 V1,V2 VSS V0 V1,V2 VSS - 26 - NJU6535 (4) 1/4 Duty, 1/3 Bias Driving fosc/384(Hz) COM1 V0 V1 V2 VSS COM2 V0 V1 V2 VSS COM3 V0 V1 V2 VSS COM4 V0 V1 V2 VSS “OFF” segment output correspond to COM1, COM2, COM3 and COM4 V0 V1 V2 VSS “ON” segment output correspond to COM1 V0 V1 V2 VSS “ON” segment output correspond to COM2 V0 V1 V2 VSS “ON” segment output correspond to COM1 and COM2 V0 V1 V2 VSS “ON” segment output correspond to COM3 V0 V1 V2 VSS “ON” segment output correspond to COM1 and COM3 V0 V1 V2 VSS “ON” segment output correspond to COM2 and COM3 V0 V1 V2 VSS “ON” segment output correspond to COM1, COM2 and COM3 V0 V1 V2 VSS “ON” segment output correspond to COM4 V0 V1 V2 VSS “ON” segment output correspond to COM2 and COM4 V0 V1 V2 VSS “ON” segment output correspond to COM1, COM2, COM3 and COM4 V0 V1 V2 VSS - 27 - NJU6535 APPLICATION CIRCUIT OSC CE SC SI SO CPU P3 P2 P1 P0 (1) 1/3 Duty, 1/2 Bias Driving (Not use E.V.R.) *2 VDD VDD V0 V1 V2 *1 *3 VSS NJU6535 VSS Output ports *4 COM1 COM2 COM3 COM1 COM2 COM3 SEG1/P0 SEG2/P1 SEG3/P2 SEG4/P3 SEG5 : : SEG40 SEG41/S0 SEG42/S1 SEG1 SEG2 SEG3 SEG4 SEG5 : : SEG40 SEG41 SEG42 LCD panel 126 segment max. S2 S3 S4 S5 K0 K1 K2 K3 K4 Key matrix 30 key max. *4 *1 *2 *3 *4 The rising time of Power source voltage at Power on and the falling time at Power off must keep over than 1 mS because of Voltage detection type Reset circuit operation. SO terminal requires external pull-up resistor connecting to Power source of external CPU because of Open-drain type output. This capacitor for bias voltage stabilization should be connected in accordance with display quality in application. General output ports and Key scan signal output terminals are duplicated-function terminals with Segment outputs. A function must be selected either Segment output or other. OSC CE SC SI SO CPU P3 P2 P1 P0 (2) 1/3 Duty, 1/3 Bias Driving (E.V.R. use) *2 VDD V0 V1 V2 VDD *1 *3 *3 NJU6535 *3 VSS VSS Output ports *4 COM1 COM2 COM3 COM1 COM2 COM3 SEG1/P0 SEG2/P1 SEG3/P2 SEG4/P3 SEG5 : : SEG40 SEG41/S0 SEG42/S1 SEG1 SEG2 SEG3 SEG4 SEG5 : : SEG40 SEG41 SEG42 LCD panel 126 segment max. S2 S3 S4 S5 K0 K1 K2 K3 K4 Key matrix 30 key max. *4 - 28 - NJU6535 *1 *2 *3 *4 The rising time of Power source voltage at Power on and the falling time at Power off must keep over than 1 mS because of Voltage detection type Reset circuit operation. SO terminal requires external pull-up resistor connecting to Power source of external CPU because of Open-drain type output. This capacitor for bias voltage stabilization should be connected in accordance with display quality in application. General output ports and Key scan signal output terminals are duplicated-function terminals with Segment outputs. A function must be selected either Segment output or other. (3) 1/4 Duty, 1/3 Bias Driving (E.V.R. use) P3 P2 P1 P0 OSC CE SC SI SO CPU *2 VDD *1 *3 *3 *3 VSS VDD V0 V1 V2 NJU6535 VSS Output ports *4 COM1 COM2 COM3 SEG40/COM4 COM1 COM2 COM3 COM4 SEG1/P0 SEG2/P1 SEG3/P2 SEG4/P3 SEG5 : : SEG39 SEG41/S0 SEG42/S1 SEG1 SEG2 SEG3 SEG4 SEG5 : : SEG39 SEG41 SEG42 LCD panel 164 segment max. S2 S3 S4 S5 K0 K1 K2 K3 K4 Key matrix 30 key max. *4 *1 *2 *3 *4 The rising time of Power source voltage at Power on and the falling time at Power off must keep over than 1 mS because of Voltage detection type Reset circuit operation. SO terminal requires external pull-up resistor connecting to Power source of external CPU because of Open-drain type output. This capacitor for bias voltage stabilization should be connected in accordance with display quality in application. General output ports and Key scan signal output terminals are duplicated-function terminals with Segment outputs. A function must be selected either Segment output or other. - 29 - NJU6535 MEMO [CAUTION] The specifications on this databook are only given for information , without any guarantee as regards either mistakes or omissions. The application circuits in this databook are described only to show representative usages of the product and not intended for the guarantee or permission of any right including the industrial rights. - 30 -