STM32 Difference between Max interface clock and max timer clock

Question

I am using TIM1 on a H743ZI with 3 PWM channels. I am trying to maximize the PWM resolution so I need to maximize the clock speed on TIM1.

the datasheet (screenshot below) gives 120MHz and 240MHz values for Max interface clock and Max timer clock.

What is the difference between the 2? I have the clocks setup as shown below, with 120MHz on APB2's peripheral clocks and 240MHz on APB2's Timer clocks.

I need a 24KHz frequency on the PWM channels so I set the ARR to 4999 which confirms the H743 is using the 120MHz value (and not the 240MHz one).

Is it because the I am using the timer in a hardware related manner - hence the "peripheral clock"?

of course, my follow up question, would be whether or not I could use the HRTIM instead?

Answer 1

Every timer consists of the counter which is fed by the timer clock and the control unit which is responsible for interfacing with the bus (core and another peripherals) which is fed by the interface clock.

More general all peripherals have a digital control part. This part is fed by the bus clock (the bus the particular peripheral is connected to). Many peripherals have more than one clock - for example ADC where the digital controller form the bus clock, and the analogue part fed from another clock source.