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Should FSMC clock be in sync with GPIO clock ?

Question asked by bruant.adrien on Jan 8, 2016

I'm using the FMSC controller on a STM32F103 to drive a TFT screen with a 8080 like interface. It seems to be working correctly but I'm wondering if there should be any particular relationship between the FMSC clock and the APB2 clock (which drives the GPIOs).

At the moment, my clock tree is set as follow:
HSE = 8MHz quartz
PLLMUL = x9 --> 72 MHz
AHB Prescaler = /1 --> 72MHz
APB2 Prescaler = /4 --> 18MHz

Does having my GPIO driven at 18 MHz limit the throughput ? Or are the alternative function pin driven independently by the FSMC clock ? I could increase the frequency of APB2 clock if needed, but it would interfere with a few peripherals and make me dig through ancient code to make it work again.