Datasheet

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 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 =CVREF circuit is powered on
0 =CV
REF circuit is powered down
bit 6 CVROE: Comparator VREF Output Enable bit
1 = CVREF voltage level is output on the CVREF 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 CVRSRC with CVRSRC/24 step size
0 =CV
RSRC range should be 0.25 to 0.719 CVRSRC with CVRSRC/32 step size
bit 4 CVRSS: Comparator VREF Source Selection bit
1 = Comparator reference source CV
RSRC = VREF+ – VREF-
0 = Comparator reference source CV
RSRC = AVDD – AVSS
bit 3-0 CVR<3:0>: Comparator VREF Value Selection 0  CVR<3:0>  15 bits
When CVRR =
1:
CVREF = (CVR<3:0>/ 24)  (CVRSRC)
When CVRR =
0:
CVREF = 1/4  (CVRSRC) + (CVR<3:0>/32)  (CVRSRC)