I have a Olimex board with a STM32F4 chip on it. In the documents it says it can run at 168Mhz. But I understand that this is configurable by changing / setting some registers. I have the following newbie questions:
1) The Olimex STM32-E407 board has a "Canned" set up in Chibios 2.6.2. Does this set up by default run the board at 168Mhz, i.e. max speed?
2) I see that the clock settings is done in os/hal/platforms/STM32F4xx and it relies on #define settings in mcuconf.h. There are some #defines like:
#define STM32_PLLM_VALUE 12
Which I assume refers to the 12 MHZ external clock crystal. There are more defines like:
#define STM32_PLLM_VALUE 12
#define STM32_PLLN_VALUE 336
#define STM32_PLLP_VALUE 2
#define STM32_PLLQ_VALUE 7
Which I think refer to the PLL = Phased Lock Loop clock circuit on the chip. I think these control some divider / pre-scalers that control the frequency that the Cortex M4 runs at. Is there some documentation somehere that describes how these #defines work?
I would like to make sure that the chip is going as fast as it can.
Many thanks, Mike.
