/*  Master SPI Test Program for Slave 68HC11 Remote I/O  */

/* Based on 68HC912B32 Master 
   Imagecraft C Vs. 6 
   March, 2000
   Don Carveth   */
   
/*  Include the Vectors.c file with no ISR Handlers defined */ 

#include <stdio.h>
#include <hc12.h>

char print_buff[80];

char sendSPI(char);

unsigned char pins[8] = {1u, 2u, 4u, 8u, 16u, 32u, 64u, 128u};
unsigned char spi_bufout[14] = {0x01u, 'A','B','C','D','E','F','G','H','I','J','K','L','M'};  /* A, B, etc, for testing */
unsigned char spi_bufin[14] = {'0','1','2','3','4','5','6','7','8','9','0','A','B','C'};
char slvMessageOut[] = "Hello - testing...testing...testing.  Oh when the Saints, bum bum bum bum..";
char slvCharIn;
int SPISendDelay = 120;	/* set SPI delay between characters */
int count_test = 0;
unsigned int t1,t2,t3,t4;
int LC = 0;			/* Loop Counter */
unsigned char k;
unsigned char slvPORTA, slvPORTC;

/* ***********************  UTILITY ROUTINES  *************************** */

int pin_stat(unsigned char volatile * port, int pin)
	{
		if ((*port & pins[pin]) == 0u)
			return 0;
		else
			return 1;
	}

void pin_set(unsigned char volatile * port, int pin)
	{
		*port = *port | pins[pin];
	}

void pin_clr(unsigned char volatile * port, int pin)
	{
		*port = *port & ~pins[pin];
	}

void msleep(int ms)
	{
		int i,j;
		for (i = 1; i < ms; i++)
			for (j = 1; j < 650; j++); /* to give 1 ms*/
	}

void run_led(void)
	{
		if (pin_stat(&PORTP,7) == 0)
			pin_set(&PORTP,7);
		else
			pin_clr(&PORTP,7);
	}

/* *********************  INITIALIZE  ************************* */

void initialize(void)
	{
	setbaud(BAUD9600);
	SC0CR1 = 0x0u;			/* SCI Setup */
	SC0CR2 = 0x2Cu;			/* Tx, Rx enable, Rx int enable */

	DDRP = 0x80u;			/* Run LED PP7 */
	
	DDRS = 0xEEu;			/* SPI Setup */
	SP0CR1 = 0x52u;
	SP0CR2 = 0x0u;
	SP0BR = 0x02u;			/*  02 for 1M, 03 for 500k, 04 for 250k, 07 for 31k */

	TSCR = 0x80u;			/* Enable timer and counters !!!!!! */
	TMSK2 = 0x03u;			/* Timer divide by 8 - 1 tick per usec, rolls over every 65 ms*/
	
	asm("andcc #0xEF");			/* Interrupts on */	
	}

/* ************************  MISC ROUTINES  ******************** */

void print_info(void)
	{
		printf(&print_buff[0], "%5d,%5d,%5d,%5d,%5d,%5d,%5d,%5d,%5d,%5d,%5d,%5d\n",
			spi_bufin[1], spi_bufin[2], spi_bufin[3], spi_bufin[4], spi_bufin[5], spi_bufin[6], 
			spi_bufin[7], spi_bufin[8], spi_bufin[9], spi_bufin[10], spi_bufin[11], spi_bufin[12]);
		}

void print_times(void)		/* For checking routine execution times */
	{
	printf(&print_buff[0],"%8d%8d%8d%8d",t1,t2,t3,t4);
	}	
	
char sendSPI(char c)
	{
	int k;
	SP0DR = c;						/* Load char and start transfer */
	for (k= 0; k < SPISendDelay; k++);	/*wait for flag and slave to load regs */
	c = SP0SR;						/* Clear SPI flag */
	c = SP0DR;						/* return SPI slave character */
	return c;
	}


/* ********************  SLAVE INTERACTION ROUTINES  ************ */

void slv_get_ports(void)			/* Get / send slave port data */
	{
		int i;
		for (i = 0; i < 14; i++) 		/* Limit value must match with slave */
			spi_bufin[i] = sendSPI(spi_bufout[i]);	/* Send / Receive SPI chars */
		slvPORTA = spi_bufin[9];	/* Assign recieved port data to labels */
		slvPORTC = spi_bufin[10]; 
	}

void slvSendMessage(void)		/* Send the string stored in slvMessageOut to the slave */ 
	{
	int k = 0;
	sendSPI(0x02);					/* Let slave know a message is coming */
	do  {
		sendSPI(slvMessageOut[k]);	/* Save message characters */
		k++;
		}
	while (slvMessageOut[k-1] != 0);  /* send until a null character is found */
	} 
	
void slvGetMessage(void)		/* Gets slave SCI messages by polling state of pin PT2 */
	{
	if (pin_stat(&PORTT,2))  {		/* Checks state of "Slave Char Rec'd" line */
		sendSPI(0x04);
		sendSPI('X');				/* Dummy send to get slave to load first char */
		do 
			putchar(sendSPI('Z'));   /* Dummy send - get slave char and sends to SCI port */
		while (pin_stat(&PORTT,2));	/* Checks state of "Slave Char Rec'd" line */ 
		}
	}	

/* ************************  MAIN ******************************* */

void main(void)
	{

	initialize();
	for (;;) 		/* Loop forever */
		{
				t1 = TCNT;		/* Used for routine execution time testing */
		slvGetMessage();
		slv_get_ports();   
				t2 = TCNT;
		print_info();   /* Turn this off to display slave SCI received characters properly */  
		slvSendMessage(); 
				t3 = TCNT;
		run_led();
/*		print_times(); */
				t4 = TCNT; 
		msleep(100);	/* 100 ms delay to set loop cycle time */
		LC++;
		}
	}