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Renesas H8S Series User Manual
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Renesas H8S Series User Manual

Lcd display using 1/4 duty drive (lcd controller/driver)
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To our customers,
st
On April 1
, 2010, NEC Electronics Corporation merged with Renesas Technology
Corporation, and Renesas Electronics Corporation took over all the business of both
companies. Therefore, although the old company name remains in this document, it is a valid
Renesas Electronics document. We appreciate your understanding.
Issued by: Renesas Electronics Corporation (http://www.renesas.com)
Send any inquiries to http://www.renesas.com/inquiry.
Old Company Name in Catalogs and Other Documents
Renesas Electronics website:
http://www.renesas.com
st
April 1
, 2010
Renesas Electronics Corporation

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Summary of Contents for Renesas H8S Series

  • Page 1 On April 1 , 2010, NEC Electronics Corporation merged with Renesas Technology Corporation, and Renesas Electronics Corporation took over all the business of both companies. Therefore, although the old company name remains in this document, it is a valid Renesas Electronics document. We appreciate your understanding.
  • Page 2 Renesas Electronics. Renesas Electronics shall not be in any way liable for any damages or losses incurred by you or third parties arising from the use of any Renesas Electronics product for an application categorized as “Specific”...

  • Page 3: Table Of Contents

    APPLICATION NOTE H8S Family LCD Display Using 1/4 Duty Drive (LCD Controller/Driver) Introduction The segment-type LCD is turned on and off by 1/4 duty drive using the LCD controller/driver and the power-supply circuit. Target Device H8S/2268 Contents Specifications ............................ 2 Functions Used ..........................

  • Page 4: Specifications

    H8S Family LCD Display Using 1/4 Duty Drive (LCD Controller/Driver) Specifications (1) This sample task shows how to use the LCD controller circuit and LCD driver circuit of the H8S/2268 to display information on an LCD module. (2) Four common signals and 16 segment signals are used for 1/4 duty display. (3) A sample LCD module connection diagram and LCD display example are shown in figure 1.

  • Page 5: Functions Used

    H8S Family LCD Display Using 1/4 Duty Drive (LCD Controller/Driver) Functions Used (1) Features of LCD Controller/Driver In this sample task information is displayed on an LCD module using the H8S/2268 internal LCD controller/driver. The features of the LCD controller/driver are listed below. •...
  • Page 6 H8S Family LCD Display Using 1/4 Duty Drive (LCD Controller/Driver) (2) Block Diagram of LCD Controller/Driver A block diagram of the LCD controller/driver used in this sample task is shown in figure 2. LCD controller/driver LCD drive power supply (built-in step-up voltage circuit) /16 to /2048...
  • Page 7 H8S Family LCD Display Using 1/4 Duty Drive (LCD Controller/Driver) (3) Functions of LCD Controller/Driver • LCD port control register (LPCR) LPCR is an 8-bit readable/writable register that selects the duty cycle, LCD driver, and pin functions. • LCD control register (LCR) LCR is an 8-bit readable/writable register that performs LCD drive power supply on/off control, display function activation control, display data control, and frame frequency selection.
  • Page 8 H8S Family LCD Display Using 1/4 Duty Drive (LCD Controller/Driver) (5) LCD RAM Map A map of LCD RAM for 1/4 duty cycle operation is shown in figure 4. bit7 bit6 bit5 bit4 bit3 bit2 bit1 bit0 H'FFFC40 SEG2 SEG2 SEG2 SEG2 SEG1...
  • Page 9 H8S Family LCD Display Using 1/4 Duty Drive (LCD Controller/Driver) (7) LCD Display/Non-Display The relationship between SEG21 and SEG22 of the 8-digit 8-segment LCD and the corresponding values set in the LCD RAM is shown in figure 6. As shown in figure 6, a setting of 1 for a bit in LCD RAM for a segment from 0 to 7 causes the corresponding segment to display, and a setting of 0 causes non-display.
  • Page 10 H8S Family LCD Display Using 1/4 Duty Drive (LCD Controller/Driver) (8) Display Data Examples Display examples for SEG21 and SEG22 of the 8-digit 8-segment LCD and the corresponding display data are shown in table 1. Table 1 Display Data Examples Display Data Symbol Display Address...
  • Page 11 H8S Family LCD Display Using 1/4 Duty Drive (LCD Controller/Driver) (9) Assignment of Functions Assignment of functions in this sample task is shown in table 2. Table 2 Assignment of Functions Elements Description LPCR Selects the duty cycle, the LCD driver, and pin functions. Performs LCD power supply on/off control, display function activation control, display data control, and frame frequency selection.

  • Page 12: Principles Of Operation

    H8S Family LCD Display Using 1/4 Duty Drive (LCD Controller/Driver) Principles of Operation (1) Hardware Settings (a) LCD Drive Power Supply Settings The H8S/2268 supports use of its built-in power supply circuit, or use of an external power supply circuit, as the LCD drive power supply.
  • Page 13 H8S Family LCD Display Using 1/4 Duty Drive (LCD Controller/Driver) (3) Principles of Operation The principles of operation of this sample task are illustrated in figure 7. 1 frame COM1 COM2 COM3 COM4 SEG36 "H " SEG35 SEG34 "8 " SEG33 SEG32 "S."...

  • Page 14: Description Of Software

    H8S Family LCD Display Using 1/4 Duty Drive (LCD Controller/Driver) Description of Software (1) Modules Table 3 shows the modules used in this sample task. Table 3 Modules Module Label Description Main routine main Performs initial settings for LCD RAM and LCD controller/driver, and displays information on LCD (2) Arguments No arguments are used in this sample task.
  • Page 15 H8S Family LCD Display Using 1/4 Duty Drive (LCD Controller/Driver) Table 4 Internal Registers Used (cont) Register Bit Name Description Address Set Value LCD control register H'FFFFC1 H'31 LCD power supply split-resistor connection control Bit 6 This bit can be used to disconnect the LCD power supply split-resistors from V when LCD display is not required in a power-down mode or when an external...
  • Page 16 H8S Family LCD Display Using 1/4 Duty Drive (LCD Controller/Driver) Table 4 Internal Registers Used (cont) Register Bit Name Description Address Set Value LCR2 LCD control register 2 H'FFFFC2 H'00 LCDAB A waveform/B waveform switching control Bit 7 Specifies whether the A waveform or B waveform is used as the LCD drive waveform.

  • Page 17: Flowchart

    H8S Family LCD Display Using 1/4 Duty Drive (LCD Controller/Driver) Flowchart (1) Main Routine main() Set the I bit to 1 to disable interrupts MSTPCRD = H'BF Clear bit 6 to 0 to clear LCD controller/driver module stop mode lcdram = LCD RAM Set LCD RAM start address in lcdram i = 0 i <...

  • Page 18: Program Listings

    H8S Family LCD Display Using 1/4 Duty Drive (LCD Controller/Driver) Program Listings SRC program listing INIT. .export _INIT .import _main .section P,CODE,ALIGN=2 _INIT: mov.l #h'ffefc0,er7 ldc.b #b'10000000,ccr ldc.b #0,exr jmp @_main .end /*******************************************************************/ /* H8S/2000 Series -H8S/2268- /* Application Note /* 'Liquid Crystal Display /* -1/4 Duty Drive, Internal Driver-' /* Function...

  • Page 19: Link Addresses

    H8S Family LCD Display Using 1/4 Duty Drive (LCD Controller/Driver) /************************************************************/ /* Main Program /************************************************************/ void main ( void ) int i; unsigned char *LCD RAM; set_imask_ccr(1); /* Interrupt Disable MSTPCRD = 0xBF; /* module stop mode is cleared LCD RAM = LCD RAM; for ( i = 0;...
  • Page 20 H8S Family LCD Display Using 1/4 Duty Drive (LCD Controller/Driver) Revision Record Description Rev. Date Page Summary 1.00 Mar.09.05 — First edition issued REJ06B0486-0100/Rev.1.00 March 2005 Page 18 of 19...
  • Page 21 (iii) prevention against any malfunction or mishap. Notes regarding these materials 1. These materials are intended as a reference to assist our customers in the selection of the Renesas Technology Corp. product best suited to the customer's application; they do not convey any license under any intellectual property rights, or any other rights, belonging to Renesas Technology Corp.