The DELAYS_TMR0 unit

Set of functions and procedures to manage precise delay slots using the TMR0 interrupt.

Demo project: None.

Authors:

 - Joep Suijs (jsuijs): Original idea of "non blocking delays" in JALLIB.

 - Vasi (funlw65): Initial port from JAL to PMP Pascal.

 - Philippe Paternotte (PPA).

Features:

This unit may handle one to many precise times, with an accuracy equal to the TMR0 interrupt rate.

The number of timer "slots" is defined at compile time to generate a code as light as it may be.

One timer "slot" may handle:

- An elapsed condition (this bit is set each time the timer has elapsed, the bit is cleared when it is read).

- A remaining ticks counter (read the remaining ticks until "terminated" or "elapsed" condition).

- A single shot mode (the timer runs once).

Note: Even if the TMR0 rate is low, having too many slots may not be a good idea because it may generate a lot of interrupt overhead that may have some incidence in the main program process. If so, it may be a better idea to count the elapsed condition of a common timer slot in separate counters in the main program and to execute actions depending on these counts.