Arduino Due: Configuring TC2 to CPCS IRQ When External Clock Fed into TCLK8

Thanks for the datasheet update link.

Well, hopefully it could work with all channels while using the waveform mode (I haven't done any testing with this mode yet, only PWM). At the beginning of my PWM setup, I needed to work with these registers:

  REG_PIOC_PDR = 0x3FC;  //B1111111100, PIO Disable Register
  REG_PIOC_ABSR = REG_PIOC_ABSR | 0x3FCu; //B1111111100, Peripheral AB Select Register
  REG_PMC_PCER1 = REG_PMC_PCER1 | 16; //Peripheral Clock Enable Register 1 (activate clock for PWM, id36, bit5 of PMC_PCSR1)
  REG_PWM_ENA = REG_PWM_SR | B1111; //PWM Enable Register | PWM Status Register (activate channels 0,1,2,3)

Not sure, but you may need to set the appropriate bits in REG_PMC_PCER0 and REG_PMC_PCER1 (re instance ID 27-35 for TC0-8).