Microchip Technology AC164139 Data Sheet
PIC24FJ256DA210 FAMILY
DS39969B-page 342
2010 Microchip Technology Inc.
REGISTER 25-1:
CVRCON: COMPARATOR VOLTAGE REFERENCE CONTROL REGISTER
U-0
U-0
U-0
U-0
U-0
R/W-0
R/W-0
R/W-0
—
—
—
—
—
CVREFP
CVREFM1
CVREFM0
bit 15
bit 8
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
CVREN
CVROE
CVRR
CVRSS
CVR3
CVR2
CVR1
CVR0
bit 7
bit 0
Legend:
R = Readable bit
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
-n = Value at POR
‘1’ = Bit is set
‘0’ = Bit is cleared
x = Bit is unknown
bit 15-11
Unimplemented: Read as ‘0’
bit 10
CVREFP: Voltage Reference Select bit (valid only when CREF is ‘1’)
1
= V
REF
+ is used as a reference voltage to the comparators
0
= The CVR (4-bit DAC) within this module provides the the reference voltage to the comparators
bit 9-8
CVREFM<1:0>: Band Gap Reference Source Select bits (valid only when CCH<1:0> = 11)
00
= Band gap voltage is provided as an input to the comparators
01
= Band gap voltage divided-by-two is provided as an input to the comparators
10
= Band gap voltage divided-by-six is provided as an input to the comparators
11
= V
REF
+ pin is provided as an input the comparators
bit 7
CVREN: Comparator Voltage Reference Enable bit
1
= CV
REF
circuit is powered on
0
= CV
REF
circuit is powered down
bit 6
CVROE: Comparator V
REF
Output Enable bit
1
= CVREF voltage level is output on the CV
REF
pin
0
= CVREF voltage level is disconnected from the CV
REF
pin
bit 5
CVRR: Comparator V
REF
Range Selection bit
1
= CV
RSRC
range should be 0 to 0.625 CV
RSRC
with CV
RSRC
/24 step size
0
= CV
RSRC
range should be 0.25 to 0.719 CV
RSRC
with CV
RSRC
/32 step size
bit 4
CVRSS: Comparator V
REF
Source Selection bit
1
= Comparator reference source CV
RSRC
= V
REF
+ – V
REF
-
0
= Comparator reference source CV
RSRC
= AV
DD
– AV
SS
bit 3-0
CVR<3:0>: Comparator V
REF
Value Selection 0
CVR<3:0> 15 bits
When CVRR = 1:
CV
CV
REF
= (CVR<3:0>/ 24)
(CV
RSRC
)
When CVRR = 0:
CV
CV
REF
= 1/4
(CV
RSRC
) + (CVR<3:0>/32)
(CV
RSRC
)