#define TIMER_DIFF(a, b, max) ((a) >= (b) ? (a) - (b) : (max) - (b) + (a))
#define TIMER_DIFF_8(a, b) TIMER_DIFF(a, b, UINT8_MAX)
#define TIMER_DIFF_16(a, b) TIMER_DIFF(a, b, UINT16_MAX)
#define TIMER_DIFF(a, b, max) ((a) >= (b) ? (a) - (b) : (max) - (b) + (a))
#define TIMER_DIFF_8(a, b) TIMER_DIFF(a, b, UINT8_MAX)
#define TIMER_DIFF_16(a, b) TIMER_DIFF(a, b, UINT16_MAX)