Which instruction is used to reset a count up counter's accumulated value?

The instruction used to reset a count up counter's accumulated value is the RESET instruction. This instruction specifically targets the accumulated value of the counter and sets it back to zero, effectively allowing the counting process to start fresh. This is particularly useful in applications where you need to reset counts after reaching a specific threshold or when starting a new counting cycle.

In contrast, the ADD instruction is used to increase the value of a counter by a specified amount, which does not serve the purpose of resetting. Similarly, the DECREMENT instruction reduces the current value but does not reset it to zero. The SET instruction is utilized to set a value to a specific number; however, it does not directly pertain to the resetting function of a count up counter. Thus, the RESET instruction stands out as the appropriate choice for this question as it fulfills the requirement of zeroing out the accumulated count.