Question: if the oscillator is 40 MHz then CLKOUT1 is 20MHz. How does this relate to actual clock cycles internal to the DSP. :

Answer: Internal clock speed is specified as the input clock frequency divided by two. For 40 MHz clock in, this means that maximum CLKOUT is 20 MHz regardless of clocking option used (i.e. divide by two, PLL x1, PLL x2). CLKOUT1 is the internal clock rate.