Update the modulo pointer. The __mod_update function updates the modulo pointer by the number of data type units specified in <amount>. <amount> may be negative. Of course, the pointer will wrap to the beginning of the modulo buffer if the pointer is advanced beyond the modulo boundaries. <amount> must be a compile time constant.
void __mod_update( int <mod_desc>, int <amount>);
Advance the modulo pointer by 2 units.
__mod_update(0, 2);