Using the HT1628 for Washing Machine Panel Display

Using the HT1628 for Washing Machine Panel Display D/N: AN0476E Introduction The HT1628 device is a RAM-mapped multifunction LCD control driver IC which operates with a 1/1 or 1/2 Duty. The device output can drive up to 116 dots with 1/1 duty or 232 dots with 1/2 duty. The software configuration features of the HT1628 make it suitable for a wide range of LCD applications. This document will introduce how to use the HT66F50 as a master MCU to control the HT1628 LCD display driving function, which can help users to better understand the HT1628 specification and applications. Functional Description LCD Panel Display Function The HT1628 LCD Demo is used for washing machine display panels. Here the display content can be roughly divided into several parts, namely the power-on initialisation state, temperature, rotation speed, wash time and other laundry process settings as well as the simulated washing process. Additionally, as the LCD display panel contains many dots, this project will use two HT1628 devices to drive two parts of the LCD display as shown in the following figure: Washing function setup Time display HT1628-1 Detection display Washing process HT1628-2 Temperature Rotation Speed Wash time Rinse times Dehydration time Drying setup AN0476E V1.00 1 / 10 January 15, 2018

Application Block Diagram The complete system plan of the HT1628 LCD Demo consists of a Top Board and a Bottom Board. Data transmission between these boards can be implemented using the serial communication interface. The bottom board provides a DC 5.0V power source to the Top Board. Top Board LCD (HT1628)-Drive Condition: 1/1 duty & 1/1 bias; Operating Voltage: 5 V Bottom Board MCU-HT66F50; Micro USB to DC 5.0V; ICP interface for code download Operating Principle This document will introduce an application example, which uses the HT66F50 as the master MCU, which communicates with the HT1628 using the serial interface to control the washing machine LCD display function. In this example, program suggestions for controlling the HT1628 device are provided to help users to have a deeper understanding of HT1628 applications. AN0476E V1.00 2 / 10 January 15, 2018

Hardware Description As mentioned above, the HT1628 LCD Demo is composed of a Top Board and a Bottom Board. TOP Board SEG'1 SEG'2 SEG'3 SEG'4 SEG'5 SEG'6 SEG'7 SEG'8 SEG'9 SEG'10 SEG'11 SEG'12 SEG'13 SEG'14 SEG'15 SEG'16 SEG'17 SEG'18 SEG'19 SEG'20 SEG'21 SEG'22 SEG'23 SEG'24 SEG'25 SEG'26 SEG'27 SEG'28 SEG'29 SEG'30 SEG'31 SEG'32 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 U1 HT1628 SEG0 SEG1 SEG2 SEG3 SEG4 SEG5 SEG6 SEG7 SEG8 SEG9 SEG10 SEG11 SEG12 SEG13 SEG14 SEG15 SEG16 SEG17 SEG18 SEG19 SEG20 SEG21 SEG22 SEG23 SEG24 SEG25 SEG26 SEG27 SEG28 SEG29 SEG30 SEG31 0R/0805 VSS R14 P1 1 2 p_a+ p_a+ 3 4 p_vdd p_vdd 5 6 p_vlcd p_vlcd 7 8 p_wrb p_data 9 10 p_cs2b 11 12 p_cs1b p_rdb 13 14 K- K- 15 16 R1 10K/0805 RD1B CS1B WR1B DATA1 VLCD1 C1 C2 C3 Top Board The Top Board schematic diagram contains a communication interface & a filter circuit, two HT1628 devices, which are 128-pin package types, for the static LCD driving circuit as well as an LCD interface circuit. The communication interface and filter circuit are used as the communicating filter between the Top Board and Bottom Board. The HT1628 drivers are setup with 1/1 duty & 1/1 bias under an operating voltage of 5V. The & SEG0~89 pins of the HT1628-U1 are connected to the LCD & SEG'1~SEG'90 The & SEG0~68 pins of the HT1628-U2 are connected to the LCD & SEG1~SEG69 p_a+ VSS 128 127 126 125 124 123 122 121 120 119 118 117 116 115 114 113 112 111 110 109 108 107 106 105 104 103 102 101 100 99 98 97 RDB CSB WRB DATA TEST DS VSS VLCD VCAP SEG115 SEG114 SEG113 SEG112 SEG111 SEG110 SEG109 SEG108 SEG107 SEG106 SEG105 SEG104 SEG103 SEG102 SEG101 SEG100 SEG99 SEG98 SEG97 SEG96 HT1628 0R/0805 SEG32 SEG33 SEG34 SEG35 SEG36 SEG37 SEG38 SEG39 SEG40 SEG41 SEG42 SEG43 SEG44 SEG45 SEG46 SEG47 SEG48 SEG49 SEG50 SEG51 SEG52 SEG53 SEG55 SEG56 SEG57 SEG58 SEG59 SEG60 SEG61 SEG62 SEG63 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 SEG'33 SEG'34 SEG'35 SEG'36 SEG'37 SEG'38 SEG'39 SEG'40 SEG'41 SEG'42 SEG'43 SEG'44 SEG'45 SEG'46 SEG'47 SEG'48 SEG'49 SEG'50 SEG'51 SEG'52 SEG'53 SEG'54 SEG'55 SEG'56 SEG'57 SEG'58 SEG'59 SEG'60 SEG'61 SEG'62 SEG'63 SEG'64 R5 A+ p_vdd R6 0R/0805 C5 C6 p_vlcd0r/0805 R4 Communicating 通信接口 Interface & 濾波電路 & Filter Circuit 0R/0805 R16 C4 0R/0805 R15 SEG95 SEG94 SEG93 SEG92 SEG91 SEG90 SEG89 SEG88 SEG87 SEG86 SEG85 SEG84 SEG83 SEG82 SEG81 SEG80 SEG79 SEG78 SEG77 SEG76 SEG75 SEG74 SEG73 SEG72 SEG71 SEG70 SEG69 SEG68 SEG67 SEG66 SEG65 SEG64 VLCD1 VLCD2 96 95 94 93 92 91 90 89 88 87 86 85 84 83 82 81 80 79 78 77 76 75 74 73 72 71 70 69 68 67 66 65 SEG'90 SEG'89 SEG'88 SEG'87 SEG'86 SEG'85 SEG'84 SEG'83 SEG'82 SEG'81 SEG'80 SEG'79 SEG'78 SEG'77 SEG'76 SEG'75 SEG'74 SEG'73 SEG'72 SEG'71 SEG'70 SEG'69 SEG'68 SEG'67 SEG'66 SEG'65 p_wrb R7 R8 C8 WR1B WR2B HT1628 HT1628 Static 靜態 LCD LCD Driver 驅動 C9 SEG1 SEG2 SEG3 SEG4 SEG5 SEG6 SEG7 SEG8 SEG9 SEG10 SEG11 SEG12 SEG13 SEG14 SEG15 SEG16 SEG17 SEG18 SEG19 SEG20 SEG21 SEG22 SEG23 SEG24 SEG25 SEG26 SEG27 SEG28 SEG29 SEG30 SEG31 SEG32 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 U2 HT1628 p_data SEG0 SEG1 SEG2 SEG3 SEG4 SEG5 SEG6 SEG7 SEG8 SEG9 SEG10 SEG11 SEG12 SEG13 SEG14 SEG15 SEG16 SEG17 SEG18 SEG19 SEG20 SEG21 SEG22 SEG23 SEG24 SEG25 SEG26 SEG27 SEG28 SEG29 SEG30 SEG31 R12 R11 10K/0805 RD2B CS2B WR2B DATA2 DATA1 R13 DATA2 C15 VLCD2 p_cs2b C12 C13 C14 R3 CS2B VSS CS1B 128 127 126 125 124 123 122 121 120 119 118 117 116 115 114 113 112 111 110 109 108 107 106 105 104 103 102 101 100 99 98 97 RDB CSB WRB DATA TEST DS VSS VLCD VCAP SEG115 SEG114 SEG113 SEG112 SEG111 SEG110 SEG109 SEG108 SEG107 SEG106 SEG105 SEG104 SEG103 SEG102 SEG101 SEG100 SEG99 SEG98 SEG97 SEG96 HT1628 SEG32 SEG33 SEG34 SEG35 SEG36 SEG37 SEG38 SEG39 SEG40 SEG41 SEG42 SEG43 SEG44 SEG45 SEG46 SEG47 SEG48 SEG49 SEG50 SEG51 SEG52 SEG53 SEG55 SEG56 SEG57 SEG58 SEG59 SEG60 SEG61 SEG62 SEG63 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 SEG33 SEG34 SEG35 SEG36 SEG37 SEG38 SEG39 SEG40 SEG41 SEG42 SEG43 SEG44 SEG45 SEG46 SEG47 SEG48 SEG49 SEG50 SEG51 SEG52 SEG53 SEG55 SEG56 SEG57 SEG58 SEG59 SEG60 SEG61 SEG62 SEG63 SEG64 C16 p_cs1b R2 C7 p_rdb R9 R10 SEG95 SEG94 SEG93 SEG92 SEG91 SEG90 SEG89 SEG88 SEG87 SEG86 SEG85 SEG84 SEG83 SEG82 SEG81 SEG80 SEG79 SEG78 SEG77 SEG76 SEG75 SEG74 SEG73 SEG72 SEG71 SEG70 SEG69 SEG68 SEG67 SEG66 SEG65 SEG64 C10 RD1B RD2B 96 95 94 93 92 91 90 89 88 87 86 85 84 83 82 81 80 79 78 77 76 75 74 73 72 71 70 69 68 67 66 65 C11 SEG69 SEG68 SEG67 SEG66 SEG65 SEG'1 SEG'2 SEG'3 SEG'4 SEG'5 SEG'6 SEG'7 SEG'8 SEG'9 SEG'10 SEG'11 SEG'12 SEG'13 SEG'14 SEG'15 SEG'16 SEG'17 SEG'18 SEG'19 SEG'20 SEG'21 SEG'22 SEG'23 SEG'24 SEG'25 SEG'26 SEG'27 SEG'28 SEG'29 SEG'30 SEG'31 SEG'32 SEG'33 SEG'34 SEG'35 SEG'36 SEG'37 SEG'38 SEG'39 SEG'40 SEG'41 SEG'42 SEG'43 SEG'44 SEG'45 SEG'46 SEG'47 SEG'48 SEG'49 SEG'50 SEG'51 SEG'52 SEG'53 SEG'54 SEG'55 SEG'56 SEG'57 SEG'58 SEG'59 SEG'60 SEG'61 SEG'62 SEG'63 SEG'64 SEG'65 SEG'66 SEG'67 SEG'68 SEG'69 SEG'70 SEG'71 SEG'72 SEG'73 SEG'74 SEG'75 SEG'76 SEG'77 SEG'78 SEG'79 SEG'80 SEG'81 SEG'82 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 U3 SEG'1 SEG'2 SEG'3 SEG'4 SEG'5 SEG'6 SEG'7 SEG'8 SEG'9 SEG'10 SEG'11 SEG'12 SEG'13 SEG'14 SEG'15 SEG'16 SEG'17 SEG'18 SEG'19 SEG'20 SEG'21 SEG'22 SEG'23 SEG'24 SEG'25 SEG'26 SEG'27 SEG'28 SEG'29 SEG'30 SEG'31 SEG'32 SEG'33 SEG'34 SEG'35 SEG'36 SEG'37 SEG'38 SEG'39 SEG'40 SEG'41 SEG'42 SEG'43 SEG'44 SEG'45 SEG'46 SEG'47 SEG'48 SEG'49 SEG'50 SEG'51 SEG'52 SEG'53 SEG'55 SEG'56 SEG'57 SEG'58 SEG'59 SEG'60 SEG'61 SEG'62 SEG'63 SEG'64 SEG'65 SEG'66 SEG'67 SEG'68 SEG'69 SEG'70 SEG'71 SEG'72 SEG'73 SEG'74 SEG'75 SEG'76 SEG'77 SEG'78 SEG'79 SEG'80 SEG'81 SEG'82 LCD1 A+ K- SEG69 SEG68 SEG67 SEG66 SEG65 SEG64 SEG63 SEG62 SEG61 SEG60 SEG59 SEG58 SEG57 SEG56 SEG55 SEG53 SEG52 SEG51 SEG50 SEG49 SEG48 SEG47 SEG46 SEG45 SEG44 SEG43 SEG42 SEG41 SEG40 SEG39 SEG38 SEG37 SEG36 SEG35 SEG34 SEG33 SEG32 SEG31 SEG30 SEG29 SEG28 SEG27 SEG26 SEG25 SEG24 SEG23 SEG22 SEG21 SEG20 SEG19 SEG18 SEG17 SEG16 SEG15 SEG14 SEG13 SEG12 SEG11 SEG10 SEG9 SEG8 SEG7 SEG6 SEG5 SEG4 SEG3 SEG2 SEG1 SEG'90 SEG'89 SEG'88 SEG'87 SEG'86 SEG'85 SEG'84 SEG'83 166 165 164 163 162 161 160 159 158 157 156 155 154 153 152 151 150 149 148 147 146 145 144 143 142 141 140 139 138 137 136 135 134 133 132 131 130 129 128 127 126 125 124 123 122 121 120 119 118 117 116 115 114 113 112 111 110 109 108 107 106 105 104 103 102 101 100 99 98 97 96 95 94 93 92 91 90 89 88 87 86 85 84 LCD interface 接口 A+ K- SEG69 SEG68 SEG67 SEG66 SEG65 SEG64 SEG63 SEG62 SEG61 SEG60 SEG59 SEG58 SEG57 SEG56 SEG55 SEG53 SEG52 SEG51 SEG50 SEG49 SEG48 SEG47 SEG46 SEG45 SEG44 SEG43 SEG42 SEG41 SEG40 SEG39 SEG38 SEG37 SEG36 SEG35 SEG34 SEG33 SEG32 SEG31 SEG30 SEG29 SEG28 SEG27 SEG26 SEG25 SEG24 SEG23 SEG22 SEG21 SEG20 SEG19 SEG18 SEG17 SEG16 SEG15 SEG14 SEG13 SEG12 SEG11 SEG10 SEG9 SEG8 SEG7 SEG6 SEG5 SEG4 SEG3 SEG2 SEG1 SEG'90 SEG'89 SEG'88 SEG'87 SEG'86 SEG'85 SEG'84 SEG'83 AN0476E V1.00 3 / 10 January 15, 2018

Bottom Board The Bottom Board schematic circuit contains a power circuit, a communicating interface circuit, an LED backlight driving circuit, an HT66F50 master MCU & RESET circuit as well as a programming interface circuit. Power Circuit Communicating Interface Programming Interface LED Backlight driver RESET Power Circuit In the Power Circuit, the 5V USB voltage passes through the TVS, then after a voltage regulation and filter processing implemented by resistor and capacitors, the voltage flows through the magnetic bead FB1 to provide power to the master MCU HT66F50 and the LCD. HT66F50 Master Circuit The data transmission between the master MCU HT66F50 and the HT1628 is implemented using an analog communication method, which is similar to the SPI, using the PC0/PC7/PC6/PD3/PD2 pins, thus implementing the LCD display control. Pin IO_LED (PA3) is used to control the LED backlight driving circuit. The backlight LED is an LED string, which contains 8 white LEDs in parallel and has a current of 160mA. AN0476E V1.00 4 / 10 January 15, 2018

Software Description This section will introduce the HT1628 serial communication and the HT1628 LCD Demo display procedure. HT1628 Serial Communication The HT1628 supports a serial communication method, implemented using 3 serial communication pins, namely the RDB, WRB and DATA pins, and a chip select pin, CSB. The pin descriptions are as follows. Pin I/O Pin Function Description CSB RDB WRB I I I DATA I/O Serial data Chip select signal. When CSB is at a high level, read/write operations on the HT1628 data and command are invalid and vice versa. Clock signal for data read. The HT1628 will transmit data to the DATA pin on the falling edge of the RDB signal. The master can read the data on the rising edge of the RDB signal. Clock signal for data write. Data on the DATA pin will be written into the HT1628 on the rising edge of the WRB signal. The timing diagram of the HT1628 data writing operation is shown below: The timing diagram of the HT1628 data reading operation is shown below: The HT1628 can be configured using software. Two mode commands are used to setup the device resources and transmit LCD display data. The Data mode ID and Command mode ID are listed as follows: Operation Status Opcode Read Data 110 Write Data 101 Read Modify Write Data 101 Control Command 100 AN0476E V1.00 5 / 10 January 15, 2018

The following commands are used to enable/disable the system oscillator and display function. Operation Opcode Command Code Note SYS DIS 100 0000-0000-X SYS EN 100 0000-0001-X Enable/disable the system oscillator LCD ON 100 0000-0010-X LCD OFF 100 0000-0011-X Enable/disable display function The timing diagram of the HT1628 compound command byte writing operation is shown below: HT1628 LCD Demo Display Procedure Step0: Power-on Initialisation state Fully bright for 3 seconds after power on, flashes 3 times with a 1Hz frequency, then enters the next stage. Step1: Simulated Washing Machine Washing Process Configuration Temperature configuration: The temperature display will change every 250ms with an order of no-display, 20 C, 30 C, 40 C, 60 C, 70 C and 90 C. After that the final setup will be 60 C, after which it will enter the rotation speed configuration. Rotation speed configuration: The rotation speed will change every 250ms with an order of 400, 600, 1600 and 1800. The final setup will be 1200, after which it will enter the wash time configuration. Wash time configuration: The wash time display will change every 250ms with an order of no-washing, 5, 10, 90 and 95 minutes. The final setup will be 20 minutes, after which it will enter the rinse time configuration. Rinse time configuration: The rinse time display will change every 250ms with an order of no-rinsing, 1, 2, 8 and 9 times. The final setup will be 2 times, after which it will enter the dehydration time configuration. Dehydration time configuration: The dehydration time display will change every 250ms with an order of no-dehydrating, 1, 2, 8 and 9 minutes. The final setup will be 5 minutes, after which it will enter the drying configuration. Drying configuration: The drying configuration will change every 500ms with an order of strong, weak and ironing. The final setup will be strong, after which it will enter the drying time configuration. Drying time configuration: The drying time display will change every 250ms with an order of no-drying, 30, 60, 90 and 120 minutes. The final setup will be 30 minutes, after which it will enter the water level configuration. AN0476E V1.00 6 / 10 January 15, 2018

Speed up configuration: Flash every 500ms, the final setup is No. Night washing configurations: Flash every 500ms, the final setup is Yes. Appointment configuration: The appointment time will incremented by 30 minutes each time from 00:00~12:00, the final setup is No. Water level configuration: The water level changes every 250ms with an order of 1, 2 and 3. The final setup will be 3, after which it will enter the laundry detergent configuration. Laundry detergent configuration: The laundry detergent configuration changes every 250ms with an order of slight, moderate and heavy dirt. The final setup will be moderate and the softener setup will be automatic, after which it will enter the next stage. Step2: Simulated Washing Machine Wash Process Water inflow and quality detection: The preset water level point flashes. When it stops this indicates that the water inflow and quality detection has finished after which the water hardness will be displayed. Laundry detergent addition: The corresponding point flashes. When it stops this indicates that the laundry detergent addition has finished. Laundry process: The rotation speed changes from 0 to 1200 and then to 0 again. The wash time and remaining time will decrement every 500ms until it reduces to 0. The rotation speed will also be 0. When the laundry is finished it will enter the next stage. Water draining: The corresponding point flashes. When it stops this indicates that the water draining has finished. Dehydration: The rotation speed changes from 0 to 1200 and then to 0 again. This indicates that the dehydration is finished. Water inflow and quality detection: The preset water level point flashes. When it stops this indicates that the water inflow and quality detection has finished after which the water hardness will be displayed. Softener addition: The corresponding point flashes. When it stops this indicates that the softener addition has finished. Rinse process: The rotation speed changes from 0 to 1200 and then to 0 again. Each time the rinse process ends the remaining time will reduce by 5 minutes and the rinse time will be decremented by 1. The water draining-dehydrating-water inflow-softener addition process will repeat until the rinse time is reduced to 0 after which it will enter the dehydration process. Dehydration: The rotation speed changes from 0 to 1200 and then to 0 again. The dehydrating time and remaining time will be decremented by 1 every 500ms until the dehydration time is reduced to 0 and the rotation speed is 0. This means that the dehydration is finished after which it will enter the next wash stage. AN0476E V1.00 7 / 10 January 15, 2018

Drying: The rotate speed changes from 0 to 1200 and then to 0 again. The drying time and remaining time will be decremented by 1 every 500ms until the drying time is reduced to 0 and the rotation speed is 0. This means that the drying is finished and also at this point the full wash process has completed. Night wash function: The rotation speed changes from 0 to 1200 and then to 0 again, for a certain interval, and after a 5 times change, the night wash process will be finished. Return to Step 1. Flowchart As mentioned above, this section will describe the HT1628 LCD Demo main program flowchart. Main Program Flowchart Description The general I/O type MCU HT66F50 acts as a master MCU, in which data transmission is implemented between this device and the slave HT1628, thus driving the LCD to show the complete simulated washing machine operation. Power on TO==1&&PDF==1 N Y Clear RAM; Sys initialisation; LCD initialisation; N F_time_50ms Y V_Lcd_Step==0? N V_Lcd_Step==1? N Y Y All on and all off with 1Hz for 3 times Washing process configuration V_Lcd_Step==2? Y Washing process N V_Lcd_Step=1 AN0476E V1.00 8 / 10 January 15, 2018

Program Example The Holtek HT8 general MCU program example: the V3C language example. HT1628_LCD(2493H +FF1FH).zip Conclusion This document has analysed the circuit structure and HT1628 LCD Demo Board program and also provided some suggestions for writing the HT1628 control program to help use the HT1628 LCD driver display function in a more flexible way. Version and Modification Information Date Author Issue 2017.12.29 王思梅 Initial version Disclaimer All information, trademarks, logos, graphics, videos, audio clips, links and other items appearing on this website ('Information') are for reference only and is subject to change at any time without prior notice and at the discretion of Holtek Semiconductor Inc. (herein after 'Holtek', 'the company', 'us', 'we' or 'our'). Whilst Holtek endeavors to ensure the accuracy of the Information on this website, no express or implied warranty is given by Holtek to the accuracy of the Information. Holtek shall bear no responsibility for any incorrectness or leakage. Holtek shall not be liable for any damages (including but not limited to computer virus, system problems or data loss) whatsoever arising in using or in connection with the use of this website by any party. There may be links in this area, which allow you to visit the websites of other companies. These websites are not controlled by Holtek. Holtek will bear no responsibility and no guarantee to whatsoever Information displayed at such sites. Hyperlinks to other websites are at your own risk. Limitation of Liability In no event shall Holtek Limited be liable to any other party for any loss or damage whatsoever or howsoever caused directly or indirectly in connection with your access to or use of this website, the content thereon or any goods, materials or services. AN0476E V1.00 9 / 10 January 15, 2018

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