PIC18F87J72-I/PT Microchip Technology, PIC18F87J72-I/PT Datasheet - Page 27

• Manufacturer Part Number: PIC18F87J72-I/PT
• Description: IC PIC MCU 8BIT 14KB FLSH 80TQFP
• Manufacturer: Microchip Technology
• Series: PIC® 18Fr

Specifications of PIC18F87J72-I/PT

• Program Memory Type: FLASH
• Program Memory Size: 128KB (64K x 16)
• Package / Case: 80-TQFP
• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 48MHz
• Connectivity: I²C, LIN, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, LCD, LVD, POR, PWM, WDT
• Number Of I /o: 51
• Ram Size: 3.8K x 8
• Voltage - Supply (vcc/vdd): 2 V ~ 3.6 V
• Data Converters: A/D 12x12b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Data Bus Width: 8 bit
• Data Ram Size: 4 KB
• Interface Type: SPI, USART, SPI, I2C
• Maximum Clock Frequency: 8 MHz
• Number Of Programmable I/os: 51
• Number Of Timers: 4
• Operating Supply Voltage: 2 V to 3.6 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 14
• Controller Family/series: PIC18F
• No. Of I/o's: 51
• Ram Memory Size: 3923Byte
• Cpu Speed: 48MHz
• No. Of Timers: 4
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant

REGISTER 3-2:
3.3
Essentially, PIC18F87J72 family devices have three
independent clock sources:
• Primary oscillators
• Secondary oscillators
• Internal oscillator
The primary oscillators can be thought of as the main
device oscillators. These are any external oscillators
connected to the OSC1 and OSC2 pins, and include
the External Crystal and Resonator modes and the
External Clock modes. If selected by the FOSC<2:0>
Configuration bits, the internal oscillator block (either
the 31 kHz INTRC or the 8 MHz INTOSC source) may
be considered a primary oscillator. The particular mode
is defined by the FOSC Configuration bits. The details
of these modes are covered in Section 3.4 “External
Oscillator Modes”.
The secondary oscillators are external clock sources
that are not connected to the OSC1 or OSC2 pins.
These sources may continue to operate even after the
 2010 Microchip Technology Inc.
bit 7
Legend:
R = Readable bit
-n = Value at POR
bit 7
bit 6
bit 5-0
INTSRC
R/W-0
Clock Sources and
Oscillator Switching
INTSRC: Internal Oscillator Low-Frequency Source Select bit
1 = 31.25 kHz device clock derived from 8 MHz INTOSC source (divide-by-256 enabled)
0 = 31 kHz device clock derived from INTRC 31 kHz oscillator
PLLEN: Frequency Multiplier PLL Enable bit
1 = PLL is enabled
0 = PLL is disabled
TUN<5:0>: Fast RC Oscillator (INTOSC) Frequency Tuning bits
011111 = Maximum frequency
•
•
000001
000000 = Center frequency. Fast RC oscillator is running at the calibrated frequency.
111111
•
•
100000 = Minimum frequency
PLLEN
R/W-0
OSCTUNE: OSCILLATOR TUNING REGISTER
W = Writable bit
‘1’ = Bit is set
R/W-0
TUN5
•
•
•
•
R/W-0
TUN4
Preliminary
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared
PIC18F87J72 FAMILY
R/W-0
TUN3
controller is placed in a power-managed mode.
PIC18F87J72 family devices offer the Timer1 oscillator
as a secondary oscillator source. This oscillator, in all
power-managed modes, is often the time base for
functions such as a Real-Time Clock (RTC). The
Timer1 oscillator is discussed in greater detail in
Section 12.0 “Timer1 Module”.
In addition to being a primary clock source in some
circumstances, the internal oscillator is available as a
power-managed mode clock source. The INTRC
source is also used as the clock source for several
special features, such as the WDT and Fail-Safe Clock
Monitor. The internal oscillator block is discussed in
more detail in Section 3.5 “Internal Oscillator
Block”.
The PIC18F87J72 family includes features that allow
the device clock source to be switched from the main
oscillator, chosen by device configuration, to one of the
alternate clock sources. When an alternate clock
source is enabled, various power-managed operating
modes are available.
R/W-0
TUN2
x = Bit is unknown
R/W-0
TUN1
DS39979A-page 27
R/W-0
TUN0
bit 0