PIC16F946-E/PT Microchip Technology, PIC16F946-E/PT Datasheet - Page 73

• Manufacturer Part Number: PIC16F946-E/PT
• Description: Microcontroller
• Manufacturer: Microchip Technology
• Series: PIC® 16Fr

Specifications of PIC16F946-E/PT

• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 20MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, LCD, POR, PWM, WDT
• Number Of I /o: 53
• Program Memory Size: 14KB (8K x 14)
• Program Memory Type: FLASH
• Eeprom Size: 256 x 8
• Ram Size: 336 x 8
• Voltage - Supply (vcc/vdd): 2 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 125°C
• Package / Case: 64-TFQFP
• Processor Series: PIC16F
• Core: PIC
• Data Bus Width: 8 bit
• Data Ram Size: 352 B
• Interface Type: SSP, I2C, AUSART, SPI
• Maximum Clock Frequency: 20 MHz
• Number Of Programmable I/os: 53
• Number Of Timers: 3
• Maximum Operating Temperature: + 125 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: 52715-96, 52716-328, 52717-734
• Development Tools By Supplier: PG164130, DV164035, DV244005, DV164005, PG164120, ICE2000, MA160011
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 10 bit, 8 Channel
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: MA160011 - DAUGHTER BOARD PICDEM LCD 16F91X
• Lead Free Status / Rohs Status: Details

4.0
4.1
The PIC16F946 has a wide variety of clock sources
and selection features to allow it to be used in a wide
range of applications while maximizing performance
and
illustrates a block diagram of the PIC16F946 clock
sources.
Clock sources can be configured from external oscillators,
quartz crystal resonators, ceramic resonators, and
Resistor-Capacitor (RC) circuits. In addition, the system
clock source can be configured from one of two internal
oscillators, with a choice of speeds selectable via
software. Additional clock features include:
• Selectable system clock source between external
• Two-Speed Clock Start-up mode, which
• Fail-Safe Clock Monitor (FSCM) designed to
FIGURE 4-1:
© 2005 Microchip Technology Inc.
or internal via software.
minimizes latency between external oscillator
start-up and code execution.
detect a failure of the external clock source (LP,
XT, HS, EC or RC modes) and switch to the
Internal Oscillator.
OSC2
OSC1
minimizing
Internal Oscillator
CLOCK SOURCES
Overview
HFINTOSC
LFINTOSC
8 MHz
31 kHz
External Oscillator
power
PIC16F946 SYSTEM CLOCK BLOCK DIAGRAM
consumption.
Sleep
500 kHz
250 kHz
125 kHz
Figure 4-1
31 kHz
8 MHz
4 MHz
2 MHz
1 MHz
Preliminary
(OSCCON<6:4>)
IRCF<2:0>
111
110
101
100
011
010
001
000
LP, XT, HS, RC, RCIO, EC
The PIC16F946 can be configured in one of eight clock
modes.
1.
2.
3.
4.
5.
6.
7.
8.
Clock source modes are configured by the FOSC<2:0>
bits
Section 16.0 “Special Features of the CPU”). The
internal clock can be generated by two oscillators. The
HFINTOSC is a high-frequency calibrated oscillator.
The LFINTOSC is a low-frequency uncalibrated
oscillator.
EC – External clock with I/O on RA6.
LP – Low-gain Crystal or Ceramic Resonator
Oscillator mode.
Oscillator mode.
HS – High-gain Crystal or Ceramic Resonator
mode.
RC – External Resistor-Capacitor (RC) with
F
RCIO – External Resistor-Capacitor with I/O on
RA6.
INTOSC – Internal oscillator with F
on RA6 and I/O on RA7.
INTOSCIO – Internal oscillator with I/O on RA6
and RA7.
XT – Medium-gain Crystal or Ceramic Resonator
OSC
in
/4 output on RA6.
the
LCD Module
Power-up Timer (PWRT)
Watchdog Timer (WDT)
Fail-Safe Clock Monitor (FSCM)
(Configuration Word)
Configuration
(OSCCON<0>)
FOSC<2:0>
SCS
PIC16F946
System Clock
(CPU and Peripherals)
Word
DS41265A-page 71
OSC
register
/4 output
(see