The choice depends on the type of firmware crystal oscillator that you put into the scheme: IR_16_2_6_7_7 - Crystal Oscillator 7.3728 mhz IR_16_2_6_7_8 - Crystal Oscillator 8 mhz
The choice depends on the type of firmware crystal oscillator that you put into the scheme:
IR_16_2_6_7_7 - Crystal Oscillator 7.3728 mhz
IR_16_2_6_7_8 - Crystal Oscillator 8 mhz