slaves having different frequencies in APB protocol

According to specifications there are no any standard frequencies for APB protocol.

Now, the peripherals connect with APB bus may have the different frequencies.

So, how APB master manage those slaves ? 

  • The APB protocol has just one clock that all connected peripherals must communicate with.

    Where you have different frequency APB devices they would either need to sit on separate APB buses (so each with an APB master), or else the APB peripheral could contain clock domain crossing synchronisation logic to connect its APB interface accesses running at PCLK to the peripherals internal logic operating at this different frequency.