IO Lcd CONTROLT6963C.C

/ * ----------------------------------------------------------
 * Program to control a T6963C-based 240x64 pixel LCD display
 * using the PC's Parallel Port (LPT1:) in bidirectional mode
 * written in Microsoft Quick C
 *
 * Written by John P. Beale May 3-4, 1997  beale@best.com
 *
 *  Based on information from Steve Lawther,
 *  "Writing Software for T6963C based Graphic LCDs", 1997 which is at
 *  http://ourworld.compuserve.com/homepages/steve_lawther/t6963c.pdf
 *
 *  and the Toshiba T6963C data sheet, also on Steve's WWW page
 *
 *  and info at: http://www.citilink.com/~jsampson/lcdindex.htm
 *               http://www.cs.colostate.edu/~hirsch/LCD.html
 *               http://www.hantronix.com/
 * ----------------------------------------------------------
 */

#include <stdio.h>
#include <stdlib.h>     // rand()
#include <conio.h>      // inp() outp() kbhit()
#include <string.h>     // strlen()
#include <graph.h>      // _settextposition(row,column) ie, (y,x)
#include <math.h>       // cos(),sin()
#include <time.h>

/* --------------------------------------------------------------
 * Pin numbers refer to pins on PC's DB25 parallel port connector.
 * Recall that SEL (pin 17), LF (14), and STROBE (1) control ouputs
 * are inverted, but Init (16) is true.
 *
 * LCD pin numbering for TOSHIBA TLX-711A-E0 (uses T6963C controller)
 *
 *  LCD Pin ----- PC Port Pin  Status Reg. bit
 * ------------------------------------------
 *  C/D  (8) <--> (17) /SEL      3
 *  /WR  (5) <--> (16) Init      2
 *  /RD  (6) <--> (14) /LF       1
 *  /CE  (7) <--> (1)  /Strobe   0
 * -----------------------
 *  D0  (11) <--> (2)  D0
 *  D1  (12) <--> (3)  D1
 *  D2  (13) <--> (4)  D2
 *  D3  (14) <--> (5)  D3
 *  D4  (15) <--> (6)  D4
 *  D5  (16) <--> (7)  D5
 *  D6  (17) <--> (8)  D6
 *  D7  (18) <--> (9)  D7
 *  GND (2)  <--> (25) GND
 * --------------------------------------------------------------
 *  FG    (1)  frame ground
 *  +5V   (3)  LCD logic supply
 *  -7.8V (4)  LCD display contrast
 *  FS    (19) font select
 *  RST   (10) active low
 */

#define CEHI outp(pcont, (inp(pcont) & 0xfe) ) // take PC 1 HI
#define CELO outp(pcont, (inp(pcont) | 0x01) ) // take PC 1 LO

#define RDHI outp(pcont, (inp(pcont) & 0xfd) ) // take PC 14 HI
#define RDLO outp(pcont, (inp(pcont) | 0x02) ) // take PC 14 LO

#define WRHI outp(pcont, (inp(pcont) | 0x04) ) // take PC 16 HI
#define WRLO outp(pcont, (inp(pcont) & 0xfb) ) // take PC 16 LO

#define CDHI outp(pcont, (inp(pcont) & 0xf7) ) // take PC 17 HI
#define CDLO outp(pcont, (inp(pcont) | 0x08) ) // take PC 17 LO

#define DATAIN  outp(pcont, (inp(pcont) | 0x20) ) // 8bit Data input
#define DATAOUT outp(pcont, (inp(pcont) & 0xdf) ) // 8bit Data output

/* ----- Definitions concerning LCD internal memory  ------ */

#define G_BASE 0x0200            // base address of graphics memory
#define T_BASE 0x0000            // base address of text memory
#define BYTES_PER_ROW 40         // how many bytes per row on screen

 /* This will be 30 with 8x8 font, 40 with 6x8 font, for both
    Text & Graphics modes. Font selection by FS pin on LCD module:
    FS=High: 6x8 font.  FS=Low: 8x8 font.                     */

/* ----------------------------------------------------------- */

#define sgn(x) ((x)>0?1:-1)
#define frand() ((float)rand()/RAND_MAX)

#define UI unsigned int
#define UL unsigned long

void delay(UL d);  // delay proportional to "d" value

void dput(int byte); // write data byte to LCD module
int dget(void);      // get data byte from LCD module
int sget(void);      // check LCD display status pbrt
void cput(int byte); // write command byte to LCD module
void lcd_setup();    // make sure control lines are at correct levels
void lcd_init();     // initialize LCD memory and display modes
void lcd_print(char *string);  // send string of characters to LCD
void lcd_clear_graph();    // clear graphics memory of LCD
void lcd_clear_text();     // clear text memory of LCD
void lcd_xy(int x, int y); // set memory pointer to (x,y) position (text)
void lcd_setpixel(int column, int row);  // set single pixel in 240x64 array

#define BASE 0x378     // base address for parallel port LPT1:
UI pdata = BASE;       // par.port data register
UI pstatus = BASE+1;   // par.port status register
UI pcont = BASE+2;     // par.port control register

#define home() dput(T_BASE%256);dput(T_BASE>>8);cput(0x24); // upper-left


#define XMAX 239        // limits of (x,y) LCD graphics drawing
#define XMIN 0
#define YMAX 63
#define YMIN 0

#define PI 3.1415926536

void main()
{
int d1;                 // data from port
int s1;                 // status register value
int c1;                 // control register value
int i;                  // generic counter
int c;                  // character to write to display
float x,y;                // coordinates on graphics screen
float xinc,yinc;
float r,theta;           // polar coords. for point dV
float theta_inc;
unsigned int cc;
char string[320];        // string to print to display
char tmpbuf[128];  // time buffer

  _clearscreen(_GCLEARSCREEN);  // Clears PC's display screen, not LCD

  printf("LCD control program.  jpb 5/3/97\n");
  printf("<esc> to quit.\n");
  lcd_setup();  // make sure control lines are at correct levels
  printf("Setup lcd sucessfully.\n");
  lcd_init();   // initialize LCD memory and display modes
  printf("Initialized lcd sucessfully.\n");

  do {  // outer loop: keypress exits

  /* --- display characters available from LCD's ROM CharGen ------ */

   lcd_clear_text();
   cput(0x97);  // Graphics & Text ON, cursor blinking
   for (c=0;c<10;c++) {
    lcd_xy(0,0);        // write text from upper left corner
    /*
    for (i=0;i<320;i++) {
      cc = (unsigned int) (c+i)%0x7f;     // display all characters
      dput(cc); cput(0xc0);               // write char, inc ptr.
    }
    */
    strcpy(string, "Hello world.");
    lcd_print(string);
    lcd_xy(0,1);        // first character, second line
    lcd_print("This is the second line.");
    lcd_xy(5,2);
    lcd_print("Here is the third line...");
    lcd_xy(0,3);
    lcd_print("...and so on and so forth.");
    lcd_xy(10,5);
    lcd_print("Press any key to exit.");
    lcd_xy(0,7);
    lcd_print("Display by John Beale ");

    /* Set time zone from TZ environment variable. If TZ is not set,
     * PST8PDT is used (Pacific standard time, daylight savings).
     */
    tzset();

    /* Display DOS-style date and time, in refresh loop */
    for (i=0;i<500;i++) {
      lcd_xy(22,0);
      _strtime( tmpbuf );
      lcd_print( tmpbuf );  // DOS-style time
      lcd_print(" ");       // intervening space
      _strdate( tmpbuf );
      lcd_print( tmpbuf );           // DOS-style date

      if (kbhit()) break;
    }
    // delay(400000);       // about 0.5 sec on 75 MHz Pentium
   }
   if (kbhit()) break;

  /* ------ bouncing line graphics "screensaver" demo ---------- */

   lcd_clear_graph();        // fill graphics memory with 0x00
   cput(0x98);  // Graphics ON, Text OFF

   x=(XMAX-XMIN)/2;
   y=(YMAX-YMIN)/2;
   r=0.3; theta = 2*PI*frand();
   theta_inc = (0.01 * frand()) - 0.005;
   for (c=0;c<12000;c++) {
     lcd_setpixel((int)x,(int)y);       // draw pixel on LCD screen
     xinc = r*cos(theta);
     yinc = r*sin(theta);
     theta += theta_inc;
     x += xinc;
     y += yinc;
     if (x>XMAX) {x=XMAX; theta = PI-theta;}
     if (y>YMAX) {y=YMAX; theta = -theta;}
     if (x<XMIN) {x=XMIN; theta = PI-theta;}
     if (y<YMIN) {y=YMIN; theta = -theta;}
     if (kbhit()) break;
     // delay(1000);       // delay calibrated on 75 MHz Pentium
     } // end for(c)
  if (kbhit()) getch();

  } while (!kbhit());

 /* --------------------------------------------------------- */

} // end main

/* Block writes would, I think, run faster if you used the DATA AUTO
   mode, eg command 0xB0. I didn't bother.
 */
void lcd_clear_graph()    // clear graphics memory of LCD
{
int i;

 dput(G_BASE%256);
 dput(G_BASE>>8);
 cput(0x24);       // addrptr at address G_BASE

 for (i=0;i<2560;i++) {
      dput(0); cput(0xc0);               // write data, inc ptr.
 } // end for(i)
} // end lcd_clear_graph()

void lcd_clear_text()
{
 int i;

 dput(T_BASE%256);
 dput(T_BASE>>8);
 cput(0x24);       // addrptr at address T_BASE

 for (i=0;i<320;i++) {
      dput(0); cput(0xc0);               // write data, inc ptr.
 } // end for(i)

} // lcd_clear_text()



void lcd_print(char *string)  // send string of characters to LCD
{
int i;
int c;

  for (i=0;i<strlen(string);i++) {
      c = string[i] - 0x20;     // convert ASCII to LCD char address
      if (c<0) c=0;
      dput(c);
      cput(0xc0);               // write character, increment memory ptr.
  } // end for

} // end lcd_string

void lcd_setpixel(int column, int row)  // set single pixel in 240x64 array
{

int addr;       // memory address of byte containing pixel to write

  addr =  G_BASE + (row*BYTES_PER_ROW)  + (column/6);
  dput(addr%256); dput(addr>>8); cput(0x24);  // set LCD addr. pointer
  cput(0xf8 | (5-(column%6)) );  // set bit-within-byte command

} // end lcd_setpixel()

void lcd_xy(int x, int y)  // set memory pointer to (x,y) position (text)
{
int addr;

  addr = T_BASE + (y * BYTES_PER_ROW) + x;
  dput(addr%256); dput(addr>>8); cput(0x24);  // set LCD addr. pointer

} // lcd_xy()

void delay(UL d)  // delay proportional to "d" value
{
UL i;
double a;

 a = 1.000;
 for (i=0;i<d;i++) {
   a = a / 1.001;
 }

} // end delay()

/* ==============================================================
 * Low-level I/O routines to interface to LCD display
 * based on four routines:
 *
 *          dput(): write data byte
 *          cput(): write control byte
 *          dget(): read data byte         (UNTESTED)
 *          sget(): read status
 * ==============================================================
 */

void lcd_setup()  // make sure control lines are at correct levels
{
 CEHI;  // disable chip
 RDHI;  // disable reading from LCD
 WRHI;  // disable writing to LCD
 CDHI;  // command/status mode
 DATAOUT; // make 8-bit parallel port an output port
} // end lcd_setup()

void lcd_init()  // initialize LCD memory and display modes
{
 dput(G_BASE%256);
 dput(G_BASE>>8);
 cput(0x42);       // set graphics memory to address G_BASE

 dput(BYTES_PER_ROW%256);
 dput(BYTES_PER_ROW>>8);
 cput(0x43);  // n bytes per graphics line

 dput(T_BASE%256);
 dput(T_BASE>>8);
 cput(0x40);       // text memory at address T_BASE

 dput(BYTES_PER_ROW%256);
 dput(BYTES_PER_ROW>>8);
 cput(0x41);  // n bytes per text line

 cput(0x80);  // mode set: Graphics OR Text, ROM CGen

 cput(0xa7);  // cursor is 8 lines high
 dput(0x00);
 dput(0x00);
 cput(0x21);  // put cursor at (x,y) location

 cput(0x97);  // Graphics & Text ON, cursor blinking
	      // (For cursor to be visible, need to set up position)

} // end lcd_init()


// ----------------------------------------------------------------
int sget(void)  // get LCD display status byte
{
int lcd_status;

  DATAIN;       // make 8-bit parallel port an input
  CDHI;         // bring LCD C/D line high (read status byte)
  RDLO;         // bring LCD /RD line low (read active)
  CELO;         // bring LCD /CE line low (chip-enable active)
  lcd_status = inp(pdata);      // read LCD status byte
  CEHI;         // bring LCD /CE line high, disabling it
  RDHI;         // deactivate LCD read mode
  DATAOUT; // make 8-bit parallel port an output port

  return(lcd_status);
} // sget()


void dput(int byte) // write data byte to LCD module over par. port
		    // assume PC port in data OUTPUT mode
{
  do {} while ((0x03 & sget()) != 0x03); // wait until display ready
  CDLO;
  WRLO;         // activate LCD's write mode
  outp(pdata, byte);          // write value to data port
  CELO;                       // pulse enable LOW > 80 ns (hah!)
  CEHI;                       // return enable HIGH
  WRHI;                       // restore Write mode to inactive

 // using my P5/75 MHz PC with ISA bus, CE stays low for 2 microseconds

} // end dput()


int dget(void)      // get data byte from LCD module
{
int lcd_byte;

  do {} while ((0x03 & sget()) != 0x03); // wait until display ready
  DATAIN; // make PC's port an input port
  WRHI;   // make sure WRITE mode is inactive
  CDLO;   // data mode
  RDLO;   // activate READ mode
  CELO;   // enable chip, which outputs data
  lcd_byte = inp(pdata);  // read data from LCD
  CEHI;   // disable chip
  RDHI;   // turn off READ mode
  DATAOUT; // make 8-bit parallel port an output port

  return(lcd_byte);
} // dget()

void cput(int byte) // write command byte to LCD module
		    // assumes port is in data OUTPUT mode
{
  do {} while ((0x03 & sget()) != 0x03); // wait until display ready

  outp(pdata, byte);  // present data to LCD on PC's port pins

  CDHI;         // control/status mode
  RDHI;         // make sure LCD read mode is off
  WRLO;         // activate LCD write mode
  CELO;         // pulse ChipEnable LOW, > 80 ns, enables LCD I/O
  CEHI;         // disable LCD I/O
  WRHI;         // deactivate write mode

} // cput()

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