Question about dsPIC30F6010A system clock

We have decided to use dsPIC30F6010A for a subsystem of an aircraft design. I realized that the dsPIC has 30 MIPS speed, however, the datasheet also states that it accepts DC to 40 MHz external clock input. My question is, if we use 40 MHz external clock oscillator as clock input, what will the CPU speed be, 40 MIPS or 30 MIPS?

Hello GoldenMaple,

Even though 40 MHz clock source could be used as clock input to dsPIC30F family chip, the dsPIC30F maximum speed is still 30 MIPS. 40 MHz input is just an option in EC (External Clock) mode to satisfy various frequency needs with the use of proper PLL and division scales. Certain voltage and temperature range must be taken into consideration in order to achieve the maximum speed.