/*************************************************************
*       jl16-6.c - Demonstrate interface to a serial LCD display
*
*       This program will print a message on an LCD display
*       using a serial interface.  It is designed to work with a
*       Matrix Orbital LK204-25 using an RS-232 interface.
*
* Revision History
* Date     Author      Description
* 11/07/07 A. Weber    First Release
* 02/26/08 A. Weber    Code cleanups
* 03/03/08 A. Weber    More code cleanups
* 04/22/08 A. Weber    Added "one" variable to make warning go away
* 09/01/11 A. Weber    Changed some function names
* 07/09/12 A. Weber    Removed code to set security bytes
* 05/29/13 A. Weber    Renamed CWJL-6.c to jl16-6.c
*************************************************************/

#include <hidef.h> /* for EnableInterrupts macro */
#include "derivative.h" /* include peripheral declarations */

void lcd_init(void);
void lcd_out(int, int, unsigned char *);
void del1m(int);
void sci_init(unsigned char, unsigned char);
void sci_out(unsigned char);
void sci_outs(unsigned char *);

/*
  This pragma sets the area for allocating variables to the zero page
  of RAM (0x00 to 0xff) for more efficient access.
*/

#pragma DATA_SEG __SHORT_SEG MY_ZEROPAGE

unsigned char delay0;
unsigned char delay1;

/*
  This pragma sets the area for allocating variables back to the default area
  of RAM as defined in the PRM file.
*/

#pragma DATA_SEG DEFAULT

/*
    Declare these strings as "const" so they are allocated in ROM
*/
const unsigned char str1[] = "12345678901234567890";
const unsigned char str2[] = ">> USC EE459L <<";
const unsigned char str3[] = ">>> jl16-6.c <<<";
const unsigned char str4[] = "- November 7, 2007 -";

void main(void) {
    unsigned char one = 1;

    // EnableInterrupts; /* enable interrupts */
    /* include your code here */

    CONFIG1_COPD = 1;           // disable COP reset

    sci_init(0, 1);             // Initialize the SCI port to 19,200
                                // Assumes a 9.8304MHz clock
                                // SCBR_SCP = 0 => Baud rate prescaler = 1
                                // SCBR_SCR = 1 => Baud rate divisor = 2

    lcd_init();                 // Initialize the LCD

    lcd_out(1, 1, (unsigned char *) str1);    // Print string on line 1
    lcd_out(3, 2, (unsigned char *) str2);    // Print string on line 2
    lcd_out(3, 3, (unsigned char *) str3);    // Print string on line 3
    lcd_out(1, 4, (unsigned char *) str4);    // Print string on line 4

    while (one) {               // Loop forever
    }
}

/*
  lcd_init - Initialize the LCD
*/
void lcd_init()
{
    del1m(500);              // Wait 500msec for the LCD to start up
    sci_out(0xfe);           // Clear the screen
    sci_out(0x58);
}

/*
  lcd_out - Print the contents of the character string "s" starting at LCD
  location "col" and "row".  The upper left corner is col=1, row=1.
  The string must be terminated by a zero byte.
*/
void lcd_out(int col, int row, unsigned char *s)
{
    sci_out((unsigned char) 0xfe);    // Set the cursor position
    sci_out((unsigned char) 0x47);
    sci_out((unsigned char) col);
    sci_out((unsigned char) row);

    sci_outs(s);                     // Output the string
}

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

/*
  sci_init - Initialize the SCI port
*/
void sci_init(unsigned char scp, unsigned char scr) {
    SCC1_ENSCI = 1;          // Enable SCI
    SCBR_SCP = scp;          // Baud rate prescaler
    SCBR_SCR = scr;          // Baud rate divisor
    SCC2_TE = 1;             // Enable transmitter
}

/*
  sci_out - Output a byte to SCI port
*/
void sci_out(unsigned char ch)
{
    while (SCS1_SCTE == 0);
    SCDR = ch;
}

/*
  sci_outs - Print the contents of the character string "s" out the SCI
  port. The string must be terminated by a zero byte.
*/
void sci_outs(unsigned char *s)
{
    unsigned char ch;

    while ((ch = *s++) != (unsigned char) NULL)
        sci_out(ch);
}

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

/*
  del1m - Delay about 1msec times the "d" argument.
*/
void del1m(int d)
{
    while (d--) {
        asm {
            ; The following code delays 1 millisecond by looping.
            ; Total time is 4 + 5 * (4 + 68 * (4 + 3) + 4 + 3) = 2439 cycles
            ; A 9.8304MHz external clock gives an internal CPU clock of
            ; 2.4576MHz (407ns/cycle).  Delay is then .993 milliseconds.
                    mov     #5,delay1   ; 4 cycles
            m1:     mov     #68,delay0  ; 4 cycles
            m0:     dec     delay0      ; 4 cycles
                    bne     m0          ; 3 cycles
                    dec     delay1      ; 4 cycles
                    bne     m1          ; 3 cycles
        }
    }
}