PIC16C642-20I/SO Microchip Technology, PIC16C642-20I/SO Datasheet - Page 53

• Manufacturer Part Number: PIC16C642-20I/SO
• Description: IC MCU OTP 4KX14 COMP 28SOIC
• Manufacturer: Microchip Technology
• Series: PIC® 16Cr

Specifications of PIC16C642-20I/SO

• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 20MHz
• Peripherals: Brown-out Detect/Reset, LED, POR, WDT
• Number Of I /o: 22
• Program Memory Size: 7KB (4K x 14)
• Program Memory Type: OTP
• Ram Size: 176 x 8
• Voltage - Supply (vcc/vdd): 4 V ~ 6 V
• Oscillator Type: External
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 28-SOIC (7.5mm Width)
• Processor Series: PIC16C
• Core: PIC
• Data Bus Width: 8 bit
• Data Ram Size: 176 B
• Interface Type: RS- 232
• Maximum Clock Frequency: 20 MHz
• Number Of Programmable I/os: 33
• Number Of Timers: 8
• Operating Supply Voltage: 3 V to 6 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: 52715-96, 52716-328, 52717-734
• Development Tools By Supplier: ICE2000, DM163022
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 10 bit
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Data Converters: -
• Connectivity: -
• Lead Free Status / Rohs Status: Details

8.0
The Voltage Reference is a 16-tap resistor ladder
network that provides a selectable voltage reference.
The resistor ladder is segmented to provide two ranges
of V
conserve power when the reference module is not
being used.
FIGURE 8-1:
FIGURE 8-2:
VREN
1996 Microchip Technology Inc.
bit7
bit 7:
bit 6:
bit 5:
bit 4:
bit 3-0: VR3:VR0 : V
R/W-0
VREN
Note:
REF
VOLTAGE REFERENCE
MODULE
values and has a power-down function to
VREN: V
1 = V
0 = V
VROE: V
1 = V
0 = V
VRR: V
1 = Low Range
0 = High Range
Unimplemented: Read as '0'
When: VRR = 1
Then: V
When: VRR = 0
Then: V
R is defined in Table 12-3.
R/W-0
VROE
REF
REF
REF
REF
V
VOLTAGE REFERENCE BLOCK DIAGRAM
VRCON REGISTER (ADDRESS 9Fh)
REF
REF
REF
REF
REF
REF
circuit powered up
circuit powered down, no I
is output on RA2 pin
is disconnected from RA2 pin
Range selection
= (VR3:VR0/ 24) • V
= 1/4 • V
REF
R/W-0
Enable
Output Enable
VRR
value selection 0
This document was created with FrameMaker 4 0 4
8R
DD
U-0
—
+ (VR3:VR0/ 32) • V
R
R/W-0
VR3
DD
DD
VR3:VR0
R
Preliminary
drain
PIC16C64X & PIC16C66X
R/W-0
VR2
16 Stages
DD
16-1 Analog Mux
15
The VRCON register, shown in Figure 8-1, controls the
operation of the Voltage Reference Module. The block
diagram is given in Figure 8-2.
R/W-0
VR1
R
bit0
R/W-0
VR0
R
R =Readable bit
W =Writable bit
U =Unimplemented bit, read
as ‘0’
- n =Value at POR reset
8R
VR3
VR2
VR1
VR0
(From VRCON<3:0>)
DS30559A-page 53
VRR