
PIC16C717/770/771
DS41120B-page 102
2002 Microchip Technology Inc.
REGISTER 10-2:
VOLTAGE REFERENCE CONTROL REGISTER (REFCON: 9BH)
R/W-0
U-0
VRHEN
VRLEN
VRHOEN
VRLOEN
—
bit 7
bit 0
bit 7
VRHEN: Voltage Reference High Enable bit (VRH = 4.096V nominal)
1
= Enabled, powers up reference generator
0
= Disabled, powers down reference generator if unused by LVD, BOR, or VRL
bit 6
VRLEN: Voltage Reference Low Enable bit (VRL = 2.048V nominal)
1
= Enabled, powers up reference generator
0
= Disabled, powers down reference generator if unused by LVD, BOR, or VRH
bit 5
VRHOEN: High Voltage Reference Output Enable bit(1)
1
= Enabled, VRH analog reference is output on RA3 if enabled (VRHEN = 1)
0
= Disabled, analog reference is used internally only(1)
bit 4
VRLOEN: Low Voltage Reference Output Enable bit
1
= Enabled, VRL analog reference is output on RA2 if enabled (VRLEN = 1)
0
= Disabled, analog reference is used internally only
bit 3-0
Unimplemented: Read as '0’
Note 1: RA2 and RA3 must be configured as analog inputs when the VREF output functions
are enabled (See ANSEL on page
25).
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