PIC16C620 Microchip Technology, PIC16C620 Datasheet - Page 44

• Manufacturer Part Number: PIC16C620
• Description: EPROM-Based 8-Bit CMOS Microcontroller
• Manufacturer: Microchip Technology

PIC16C62X
EXAMPLE 8-1:
8.2
The full range of V
the construction of the module. The transistors on the
top and bottom of the resistor ladder network
(Figure 8-2) keep V
The Voltage Reference is V
the V
tested absolute accuracy of the Voltage Reference can
be found in Table 12-3.
8.3
When the device wakes up from sleep through an
interrupt or a Watchdog Timer time-out, the contents of
the VRCON register are not affected. To minimize
current consumption in SLEEP mode, the Voltage
Reference should be disabled.
FIGURE 8-3:
TABLE 8-1:
DS30235G-page 44
MOVLW
MOVWF
BSF
MOVLW
MOVWF
MOVLW
MOVWF
BCF
CALL
Address
9Fh
1Fh
85h
Note:
Note 1: R is dependent upon the Voltage Reference Configuration VRCON<3:0> and VRCON<5>.
REF
Voltage Reference Accuracy/Error
Operation During Sleep
output changes with fluctuations in V
Name
VRCON
CMCON
TRISA
- = Unimplemented, read as "0"
0x02
CMCON
STATUS,RP0
0x07
TRISA
0xA6
VRCON
STATUS,RP0
DELAY10
VOLTAGE REFERENCE OUTPUT BUFFER EXAMPLE
REGISTERS ASSOCIATED WITH VOLTAGE REFERENCE
SS
Module
REF
V
VOLTAGE REFERENCE
CONFIGURATION
REF
to V
C2OUT
VREN
Bit 7
from approaching V
—
DD
Impedance
Reference
DD
cannot be realized due to
; 4 Inputs Muxed
; to 2 comps.
; go to Bank 1
; RA3-RA0 are
; outputs
; enable V
; low range
; set V
; go to Bank 0
; 10 s delay
Voltage
Output
C1OUT
VROE
derived and therefore,
Bit 6
R
—
(1)
R
<3:0>=6
Bit 5
VRR
REF
—
—
RA2
SS
TRISA4
or V
DD
Bit 4
•
—
—
. The
Preliminary
DD
.
TRISA3
Bit 3
VR3
CIS
8.4
A device reset disables the Voltage Reference by clear-
ing bit V
the reference from the RA2 pin by clearing bit V
(VRCON<6>) and selects the high voltage range by
clearing bit V
bits, VRCON<3:0>, are also cleared.
8.5
The Voltage Reference Module operates independently
of the comparator module. The output of the reference
generator may be connected to the RA2 pin if the
TRISA<2> bit is set and the V
set. Enabling the Voltage Reference output onto the
RA2 pin with an input signal present will increase cur-
rent consumption. Connecting RA2 as a digital output
with V
tion.
The RA2 pin can be used as a simple D/A output with
limited drive capability. Due to the limited drive
capability, a buffer must be used in conjunction with the
Voltage Reference output for external connections to
V
technique.
REF
TRISA2
Bit 2
CM2
VR2
. Figure 8-3
REF
+
–
REN
Effects of a Reset
Connection Considerations
enabled will also increase current consump-
TRISA1
Bit 1
(VRCON<7>). This reset also disconnects
CM1
VR1
RR
•
(VRCON<5>). The V
TRISA0
V
shows
Bit 0
CM0
VR0
REF
Output
1998 Microchip Technology Inc.
000- 0000 000- 0000
00-- 0000 00-- 0000
---1 1111 ---1 1111
an
Value On
ROE
POR
example
bit, VRCON<6>, is
REF
value select
Value On
All Other
Resets
buffering
ROE