// Handel-C decade counter and test with seven-segment display decoder

void increment_decade(unsigned 4 *count, unsigned 1 Hold);
macro proc SevenSegDecoder (bcd, seg);
extern "C++" void printDisplay(unsigned 8 seg1, unsigned 8 seg2);

set clock = external "Dummy";

void main (void)
{
	// Declarations
	unsigned 1 stop;
	unsigned 8 i;
	unsigned 4 count[2];
	unsigned 1 hold;
	unsigned 8 seg1, seg2;

	hold = 0;

	par {
		stop = 0;
		count[0] = 0;
		count[1] = 0;
	}

	par {

		// Stimulus
		{
			// Count a while
			for (i = 0; i < 8; i++)
				;						// Takes 9 cycles
										// => count = "09"
			// Hold a while
			hold = 1;					// + 1 cycle  = 10
										// => count = "01"
			for (i = 0; i < 8; i++)
				;						// + 9 cycles = 19
										// => count = "10"
			// Count right round
			hold = 0;					// + 1 cycle  = 20
										// => count = "10"
			for (i = 0; i < 89; i++)
				;						// + 90 cycles = 110
										// => count = "00"
			// Stop the simulator
			stop = 1;
		}

		// Simulation output
		while (!stop)
			printDisplay(seg1, seg2);

		// Call the counter
		while (!stop)
			increment_decade(count, hold);

		// First seven segment display
		while (!stop)
			SevenSegDecoder(count[1], seg1);

		// Second seven segment display
		while (!stop)
			SevenSegDecoder(count[0], seg2);

	}
}

void increment_decade(unsigned 4 *count, unsigned 1 Hold)
{
	if (Hold)
		count[0] = count[0];		/* You have to do something! */
	else if ( count[0] == 9 ) par {	/* "par" ensures one cycle */
		count[0] = 0;
		if ( count[1] == 9 )
			count[1] = 0;
		else
			count[1]++;
	} else
		count[0]++;
}

macro proc SevenSegDecoder (bcd, seg) {
	switch (bcd) {
		case 0  : seg = 0b00111111; break;
		case 1  : seg = 0b00000110; break;
		case 2  : seg = 0b01011011; break;
		case 3  : seg = 0b01001111; break;
		case 4  : seg = 0b01100110; break;
		case 5  : seg = 0b01101101; break;
		case 6  : seg = 0b01111100; break;
		case 7  : seg = 0b00000111; break;
		case 8  : seg = 0b01111111; break;
		case 9  : seg = 0b01100111; break;
		default : seg = 0b10001000; break;
	}
}