When trying to understand the hardware connections between the STM32F103RB and OV7670 camera module we found out that the camera module needs an external clock frequency of 10 - 40 (MHz). In order to provide the required clock frequency we needed to reconfigure out clock tree path:
Provided that up until now we have been working with the default HSI clock frequency of 8MHz we came up with a plan that will allow us to keep the clock sources of the different peripherals untouched while providing a frequency of 32MHz to the MCO (Microcontroller clock output).
Overview
When trying to understand the hardware connections between the STM32F103RB and OV7670 camera module we found out that the camera module needs an external clock frequency of 10 - 40 (MHz). In order to provide the required clock frequency we needed to reconfigure out clock tree path:
This image was taken from The Mighty Ducks (Team #1)
Reconstructing
Provided that up until now we have been working with the default HSI clock frequency of 8MHz we came up with a plan that will allow us to keep the clock sources of the different peripherals untouched while providing a frequency of 32MHz to the MCO (Microcontroller clock output).
Links
Changing the Clock Frequency STM32F1 via Registers - Code example :: how to change the clock frequency CMSIS-Core (Cortex-M) - There is a function SystemCoreClockUpdate() we didn't know whether to use or not... this is its source STM32F103 RCC-Use HSE/HSI to configure the clock - MCO GPIO initialization