Datasheet
Analog Comparator (S08ACMPV2)
MC9S08QG8 and MC9S08QG4 Data Sheet, Rev. 5
Freescale Semiconductor 113
8.4 Functional Description
The analog comparator can be used to compare two analog input voltages applied to ACMP+ and ACMP–; 
or it can be used to compare an analog input voltage applied to ACMP– with an internal bandgap reference 
voltage. ACBGS is used to select between the bandgap reference voltage or the ACMP+ pin as the input 
to the non-inverting input of the analog comparator. The comparator output is high when the non-inverting 
input is greater than the inverting input, and is low when the non-inverting input is less than the inverting 
input. ACMOD is used to select the condition which will cause ACF to be set. ACF can be set on a rising 
edge of the comparator output, a falling edge of the comparator output, or either a rising or a falling edge 
(toggle). The comparator output can be read directly through ACO. The comparator output can be driven 
onto the ACMPO pin using ACOPE.










