// 11.0592MHz XTAL
#include "sdccF000.h"   //register definitions

#define    TRUE    1
#define FALSE    0
#define    TX2                        P0_6    //bit bashed UART2 TX
#define RX2                        P0_7    //bit bashed UART2 RX

//Prototypes
void config_mcu(void);
void UART1_TX(char character);
void UART1_send_string(unsigned char string[]);



//Global variables
int test = 0;
int i = 0;
int k = 0;
unsigned char l;
unsigned int j;
char n = 0;
__bit UART1_sample = FALSE;
unsigned char bit_mask = 0x01;

void main(void)

{
    //setup the MCU's registers
    config_mcu();

    UART1_send_string("Hello World!");  //send a message out our bit bashed 9600 UART

    while(TRUE)
    {
        if (RI == 1)   
        {
            UART1_TX(SBUF);  //send what ever we receive on the built in UART to our bit bashed UART
            RI = 0;      
        }
    }
}

void config_mcu()
{
    int i = 0;

    //Disable the WatchDog
    WDTCN = 0xDE;
    WDTCN = 0xAD;

    //UART_init
    // setup the UART for 4800, 8, N, 1
    SCON      = 0x52;
    CKCON     = 0x24;
    T2CON     = 0x34;
    RCAP2H    = 0xFF;
    RCAP2L    = 0xB8;   
    TH2       = 0xFF;
    TL2          = 0xB8;

    //Timer 0 - use for 9600 baud bit-bashed UART
    TMOD = 0x01;
    TCON = 0x10; //enable timer0
    TH0 = 0xFF;        //these valuse give a 4.8kHz clock which gives a 9600 baud rate
    TL0 = 0xA1;

    //port_IO_init
    // P0.0  -  SCL   (I2C), Open-Drain 
    // P0.1  -  SDA   (I2C), Open-Drain
    // P0.2  -  TX   (UART), Push-Pull 
    // P0.3  -  RX   (UART), Push-Pull 
    XBR0    = 0x05;    //UART assigned to Port0.2 and 0.3
    XBR1    = 0x00;
    XBR2    = 0x40;    //Weak pull ups enabled for Open Drain outputs
    PRT0CF    = 0xFC;
    PRT1CF    = 0xF0;    //0-3 Open-Drain, 4-7 Push-Pull
    PRT2CF  = 0xFF;
    PRT3CF  = 0xFF;

    //oscillator_init
    OSCXCN    = 0x67;
    for (i = 0; i < 3000; i++);  // Wait 1ms for initialization
    while ((OSCXCN & 0x80) == 0);
    OSCICN    = 0x08;

    //interrupts_init
    IE = 0x82;
    IP = 0x02;  //Timer 0 high priority
}

void UART1_send_string(unsigned char string[])
{
   l = 0;
   while (string[l] != 0x00)
   {
      UART1_TX(string[l]);
      l++;
   }
   l = 0;
}

void UART1_TX(char character)
{
    //convert character to serial, and send it out TX2
    //This routine is, basically, a parallel to serial converter
    //Characters are sent LSB first, 9600 baud
    bit_mask = 0x01;

    // Send a start bit - first we'll keep the line idle for one more clock cycle - I found this stops glitches
    //I was getting occasionally with the first byte sent out
    while (UART1_sample == FALSE);
    TX2 = TRUE;
    UART1_sample = FALSE;
    //Now we'll start... This is the start bit
    while (UART1_sample == FALSE);
    TX2 = FALSE;
    UART1_sample = FALSE;
    //send the byte - LSB first
    for (k = 0;  k < 8; k++)
    {
        // determine whether to put a 0 or 1 on to TX2
        while (UART1_sample == FALSE);
        if ((character & bit_mask) > 0) TX2 = TRUE;
            else TX2 = FALSE;
        UART1_sample = FALSE;
        // Shift bit_mask right 1 bit 0x01->0x02->0x04->0x08->0x10->0x20->0x40->0x80
        bit_mask = bit_mask << 1;  
    } 
    //send a stop bit
    while (UART1_sample == FALSE);
    TX2 = TRUE;
    UART1_sample = FALSE;
}

/**********  INTERRUPT ROUTINES  ****************/
void Timer0_Isr (void) __interrupt (1)     //interrupt every 418uS -             
{
    //TX2 = !TX2;  //used to test the timer period is correct - if it is correct, you'll see a whole bunch of "U" characters in your terminal window
    UART1_sample = TRUE;
    TH0 = 0xFF;
    TL0 = 0xA1;
}