PIC16LF720_11 Datasheet, PDF (87/244 Pages) Microchip Technology – 20-Pin Flash Microcontrollers with nanoWatt XLP Technology

PIC16(L)F720/721
10.0 FIXED VOLTAGE REFERENCE
This device contains an internal voltage regulator. To
provide a reference for the regulator, a band gap refer-
ence is provided. This band gap is also user accessible
via an A/D converter channel.
User level band gap functions are controlled by the
FVRCON register, which is shown in Register 10-1.
REGISTER 10-1: FVRCON: FIXED VOLTAGE REFERENCE REGISTER
R-q
R/W-0
R/W-0
R/W-0
U-0
U-0
FVRRDY
FVREN
TSEN
TSRNG
—
—
bit 7
R/W-0
ADFVR1
R/W-0
ADFVR0
bit 0
Legend:
R = Readable bit
W = Writable bit
-n = Value at POR
‘1’ = Bit is set
q = Value depends on condition
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared
x = Bit is unknown
bit 7
bit 6
bit 5
bit 4
bit 3-2
bit 1-0
FVRRDY⁽¹⁾: Fixed Voltage Reference Ready Flag bit
0 = Fixed Voltage Reference output is not active or stable
1 = Fixed Voltage Reference output is ready for use
FVREN⁽²⁾: Fixed Voltage Reference Enable bit
0 = Fixed Voltage Reference is disabled
1 = Fixed Voltage Reference is enabled
TSEN: Temperature Indicator Enable bit⁽³⁾
0 = Temperature indicator is disabled
1 = Temperature indicator is enabled
TSRNG: Temperature Indicator Range Selection bit⁽³⁾
0 = VOUT = VDD - 4VT (High Range)
1 = VOUT = VDD - 2VT (Low Range)
Unimplemented: Read as ‘0’
ADFVR<1:0>: A/D Converter Fixed Voltage Reference Selection bits
00 = A/D Converter Fixed Voltage Reference Peripheral output is off
01 = A/D Converter Fixed Voltage Reference Peripheral output is 1x (1.024V)
10 = A/D Converter Fixed Voltage Reference Peripheral output is 2x (2.048V)⁽²⁾
11 = A/D Converter Fixed Voltage Reference Peripheral output is 4x (4.096V)⁽²⁾
Note 1: FVRRDY is always ‘1’ for the PIC16F720/721 devices.
2: Fixed Voltage Reference output cannot exceed VDD.
3: See Section 11.0 “Temperature Indicator Module” for additional information.
TABLE 10-1: SUMMARY OF ASSOCIATED FIXED VOLTAGE REFERENCE REGISTERS
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Value on
POR, BOR
Value on
all other
Resets
FVRCON
Legend:
FVRRDY FVREN TSEN TSRNG
—
—
ADFVR1 ADFVR0 ^{q000 --00 q000 --00}
x = unknown, u = unchanged, — = unimplemented read as ‘0’, q = value depends on condition. Shaded cells are not
used for ADC module.
 2011 Microchip Technology Inc.
Preliminary
DS41430B-page 87