Clarification needed on BRG calculation
I am working on a PI24EP512GU810 and using its I2C2 module. The family reference manual (http://ww1.microchip.com/downloads/en/DeviceDoc/70000195g.pdf
) shows the formula to calculate the value for the I2C2BRG register at page 19.
The formula mentions a "Delay" factor that is "usually" between 110 ns and 130 ns. Is it possible to know exactly what this delay is and what it refers to? I could not find any other mention in the FRM and the Datasheet.
More importantly, for my application I configured the MCU to run at 120MHz. This means that the FCY factor used in the above formula is 60'000'000, which results into a BRG value over 511 for a required frequency of 100KHz. Unfortunately the I2C2BRG register is only 9 bits wide, so it's not possible to provide a value > 511.
I can settle for a slightly higher frequency, but does this mean that some I2C clock frequencies are locked to certain system clock values?