PIC18F2220/2320/4220/4320
FIGURE 21-2:
VOLTAGE REFERENCE OUTPUT BUFFER EXAMPLE
(1)
R
RA2
CVREF
Module
+
–
CVREF Output
Voltage
Reference
Output
Impedance
Note 1: R is dependent upon the voltage reference configuration bits (CVRCON<3:0> and CVRCON<5>).
TABLE 21-1: REGISTERS ASSOCIATED WITH COMPARATOR VOLTAGE REFERENCE
Value on
all other
Resets
Value on
POR
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
CVRCON CVREN CVROE CVRR
—
CVR3
CIS
CVR2
CM2
RA2
CVR1
CM1
RA1
CVR0 000- 0000 000- 0000
CMCON
TRISA
C2OUT C1OUT C2INV C1INV
RA7(1) RA6(1)
RA5 RA4
CM0
RA0
0000 0111 0000 0111
1111 1111 1111 1111
RA3
Legend: x= unknown, u = unchanged, - = unimplemented, read as ‘0’.
Shaded cells are not used with the comparator voltage reference.
Note 1: These pins are enabled based on oscillator configuration (see Configuration Register 1H).
2003 Microchip Technology Inc.
DS39599C-page 229
MICROCHIP [ MICROCHIP ]
