Which is better: lower prescaler (PSC) value or lower period (ARR) value?

[JBond.1]

Hi, I wonder which one is better for Timer setup:

1. lower prescaler (PSC) value and higher period (ARR) value?
2. lower period (ARR) value and higher prescaler (PSC) value?

[waclawek.jan]

What is"better"?

Whichever setting suits your application is OK. Higher prescaler might theoretically lead to lower power consumption, but the difference will be probably entirely negligible.

JW

[JBond.1]

Lower power consumption is better, so I will try to choose larger PSC and lower ARR if possible.

Like at 72Mhz cpu:

1ms timer PSC = 7199 ARR = 9

100ms timer PSC = 59999 ARR = 119

[TDK]

I usually prefer lower PSC in order to have better resolution, but sometimes resolution doesn't matter. Note that ARR needs to be nonzero.