PIC16C782 Microchip Technology Inc., PIC16C782 Datasheet - Page 63

• Manufacturer Part Number: PIC16C782
• Description: 8-bit Cmos Microcontrollers With A/d, D/a, Opamp, Comparators And Psmc
• Manufacturer: Microchip Technology Inc.

7.0
The Voltage Reference module provides an on-chip
nominal 3.072V reference voltage for the following:
• ADC converter
• DAC converter
• VR output on the RB0/INT/AN4/VR pin
The source for the reference voltage comes from a
bandgap reference.
The control register for this module is the REFCON
register shown in Register 7-1.
REGISTER 7-1:
TABLE 7-1:
Address
09Bh
2001 Microchip Technology Inc.
Note 1: If the V
VOLTAGE REFERENCE
MODULE (V
2: When VREN = 1 and VROE = 1, the out-
bit 7-4
bit 3
bit 2
bit 1-0
REFCON
DAC, ADC, or V
must
(REFCON<3>).
put driver for RB0/INT/AN4/V
driven tri-state and the analog driver for
the V
RB0 will return a ‘0’.
Name
R
SUMMARY OF REGISTERS ASSOCIATED WITH V
output will be enabled. A read of
R
be
Bit 7 Bit 6
VOLTAGE REFERENCE CONTROL REGISTER (REFCON: 9Bh)
Legend:
R = Readable bit
- n = Value at POR
module is to be used by the
Unimplemented: Read as ‘0’
VREN: Voltage Reference Enable bit (V
1 = V
0 = V
VROE: Voltage Reference Output Enable bit
If VREN = 1:
1 = Enabled, V
0 = Voltage reference is not available externally
If VREN = 0:
This bit is ignored
Unimplemented: Read as ‘0’
bit 7
—
R
enabled
U-0
—
)
R
R
R
reference is enabled
reference is disabled
—
output:, the V
Bit 5
R
using
U-0
—
—
voltage reference is output on RB0
R
R
module
Bit 4
will be
VREN
—
Preliminary
U-0
W = Writable bit
’1’ = Bit is set
—
VREN
Bit 3
U-0
R
Setting the VREN flag (REFCON<3>), enables the
module. Following initial start-up, the module should be
allowed to stabilize for best accuracy. See Section 17.0
for information concerning stabilization times and
conditions.
To route the reference voltage to the external RB0/INT/
AN4/V
set.
7.1
A device RESET clears the REFCON register, dis-
abling the voltage reference.
7.2
A summary of the registers associated with V
shown in Table 7-1.
—
VROE
Bit 2
= 3.072V nominal)
R
pin, the VROE flag (REFCON<2>) must be
Effects of RESET
Registers Associated with V
U = Unimplemented bit, read as ‘0’
’0’ = Bit is cleared
R/W-0
VREN
Bit 1
—
R
PIC16C781/782
Bit 0
—
R/W-0
VROE
---- 00-- ---- 00--
Value on:
POR,
BOR
x = Bit is unknown
U-0
DS41171A-page 61
—
Value on
RESETS
all other
R
U-0
—
bit 0
R
is