#include <c8051f120.h>
#include "hw_rng.h"

void hwrng_init( ) {
	char save = SFRPAGE;
	SFRPAGE = TMR3_PAGE;

	RCAP3L = 0x00;
	RCAP3H = 0x00; 
	TMR3CF = 0x08; /* no special features, clock divider = 1 */
	TMR3CN = 0x04; /* enable timer3 in auto-reload mode */

	SFRPAGE = save;
}

unsigned short hwrng_random( ) {
	unsigned short ret;
	char save = SFRPAGE;
	SFRPAGE = TMR3_PAGE;
	
	ret = (TMR3H << 8) | (TMR3L);

	SFRPAGE = save;
	return ret;
}