Z51F0410 Datasheet, PDF (135/184 Pages) Zilog, Inc. – Z8051 Series 8-Bit Microcontrollers

Z51F0410
Product Specification
4.9 Analog Comparator
4.9.1 Overview
The Analog Comparator compares the input values on the positive pin AN5 and the negative pin
AN4. When the voltage on the positive pin AN5 is higher than the voltage on the negative pin AN4,
the Analog Comparator output, ACOUT, is set.
4.9.2 Block Diagram
B/G
Vf
AN4
ACBG
MUX
AN5
ADC MUX
Output
MUX
AMUXENB
(ADCM2.3)
ACE
Comparator
ACIE
Interrupt
Select
ACISM[1:0]
ACIF
Analog
Comparator
Interrupt
ACO
Figure 4.43 Analog Comparator Block Diagram
4.9.3 IN/OUT signal description
ACE : This enables Analog Comparator. When ACE is ‘0’, the output of Comparator goes LOW.
BGR : Band Gap Reference Voltage
ACBG : This selects (-) input source between BGR and AN4. When ACBG is ‘1’, the (-) input to AC is
BGR.
AN4 : This can be (-) input to the AC, and comes directly from external analog pad.
AN5 : This can be (+) input to the AC, and comes directly from external analog pad.
AMUXENB : This selects (+) input source between multiplexed output of ADC and AN5. AMUXENB is
the inverted signal of AMUXEN bit in ADCM2 register. When AMUXENB is ‘0’, the (+) input to AC
comes from ADC module which is selected by ADSEL[3:0], the channel selection bits in ADCM
register.
ACOUT : This is the output of Comparator.
PS029502-0212
PRELIMINARY
132