PIC18F4455-I/P Microchip Technology, PIC18F4455-I/P Datasheet - Page 25

• Manufacturer Part Number: PIC18F4455-I/P
• Description: IC PIC MCU FLASH 12KX16 40DIP
• Manufacturer: Microchip Technology
• Series: PIC® 18Fr

Specifications of PIC18F4455-I/P

• Program Memory Type: FLASH
• Program Memory Size: 24KB (12K x 16)
• Package / Case: 40-DIP (0.600", 15.24mm)
• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 48MHz
• Connectivity: I²C, SPI, UART/USART, USB
• Peripherals: Brown-out Detect/Reset, HLVD, POR, PWM, WDT
• Number Of I /o: 35
• Eeprom Size: 256 x 8
• Ram Size: 2K x 8
• Voltage - Supply (vcc/vdd): 4.2 V ~ 5.5 V
• Data Converters: A/D 13x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Processor Series: PIC18F
• Core: PIC
• Data Bus Width: 8 bit
• Data Ram Size: 2 KB
• Interface Type: SPI/I2C/EAUSART
• Maximum Clock Frequency: 48 MHz
• Number Of Programmable I/os: 35
• Number Of Timers: 4
• Operating Supply Voltage: 2 V to 5.5 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: Through Hole
• 3rd Party Development Tools: 52715-96, 52716-328, 52717-734, 52712-325, EWPIC18
• Development Tools By Supplier: PG164130, DV164035, DV244005, DV164005, PG164120, ICE2000, ICE4000, DV164136, DM163025
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 13-ch x 10-bit
• Package: 40PDIP
• Device Core: PIC
• Family Name: PIC18
• Maximum Speed: 48 MHz
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: I3-DB18F4550 - BOARD DAUGHTER ICEPIC3DM163025 - PIC DEM FULL SPEED USB DEMO BRDDVA18XP400 - DEVICE ADAPTER 18F4220 PDIP 40LD444-1001 - DEMO BOARD FOR PICMICRO MCUACICE0206 - ADAPTER MPLABICE 40P 600 MIL
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

2.0
2.1
Devices in the PIC18F2455/2550/4455/4550 family
incorporate a different oscillator and microcontroller
clock system than previous PIC18F devices. The addi-
tion of the USB module, with its unique requirements
for a stable clock source, make it necessary to provide
a separate clock source that is compliant with both
USB low-speed and full-speed specifications.
To accommodate these requirements, PIC18F2455/
2550/4455/4550 devices include a new clock branch to
provide a 48 MHz clock for full-speed USB operation.
Since it is driven from the primary clock source, an
additional system of prescalers and postscalers has
been added to accommodate a wide range of oscillator
frequencies. An overview of the oscillator structure is
shown in Figure 2-1.
Other oscillator features used in PIC18 enhanced
microcontrollers, such as the internal oscillator block
and clock switching, remain the same. They are
discussed later in this chapter.
2.1.1
The operation of the oscillator in PIC18F2455/2550/
4455/4550 devices is controlled through two Configu-
ration registers and two control registers. Configuration
registers, CONFIG1L and CONFIG1H, select the
oscillator mode and USB prescaler/postscaler options.
As Configuration bits, these are set when the device is
programmed and left in that configuration until the
device is reprogrammed.
The OSCCON register (Register 2-2) selects the Active
Clock mode; it is primarily used in controlling clock
switching in power-managed modes. Its use is
Register”.
The OSCTUNE register (Register 2-1) is used to trim
the INTRC frequency source, as well as select the
low-frequency clock source that drives several special
features. Its use is described in Section 2.2.5.2
“OSCTUNE Register”.
2.2
PIC18F2455/2550/4455/4550 devices can be operated
in twelve distinct oscillator modes. In contrast with pre-
vious PIC18 enhanced microcontrollers, four of these
modes involve the use of two oscillator types at once.
Users can program the FOSC3:FOSC0 Configuration
bits to select one of these modes:
© 2007 Microchip Technology Inc.
discussed in Section 2.4.1 “Oscillator Control
OSCILLATOR
CONFIGURATIONS
Overview
Oscillator Types
OSCILLATOR CONTROL
PIC18F2455/2550/4455/4550
Preliminary
1.
2.
3.
4.
5.
6.
7.
8.
9.
10. INTXT
11. INTIO
12. INTCKO Internal Oscillator used as
2.2.1
Because of the unique requirements of the USB module,
a different approach to clock operation is necessary. In
previous PIC
were driven by a single oscillator source; the usual
sources were primary, secondary or the internal oscilla-
tor. With PIC18F2455/2550/4455/4550 devices, the pri-
mary oscillator becomes part of the USB module and
cannot be associated to any other clock source. Thus,
the USB module must be clocked from the primary clock
source; however, the microcontroller core and other
peripherals can be separately clocked from the second-
ary or internal oscillators as before.
Because of the timing requirements imposed by USB,
an internal clock of either 6 MHz or 48 MHz is required
while the USB module is enabled. Fortunately, the
microcontroller and other peripherals are not required
to run at this clock speed when using the primary
oscillator. There are numerous options to achieve the
USB module clock requirement and still provide flexibil-
ity for clocking the rest of the device from the primary
oscillator source. These are detailed in Section 2.3
“Oscillator Settings for USB”.
XT
XTPLL Crystal/Resonator with PLL enabled
HS
HSPLL High-Speed Crystal/Resonator
EC
ECIO
ECPLL External Clock with PLL enabled
ECPIO External Clock with PLL enabled,
INTHS Internal Oscillator used as
OSCILLATOR MODES AND
USB OPERATION
®
Crystal/Resonator
High-Speed Crystal/Resonator
with PLL enabled
External Clock with F
External Clock with I/O on RA6
and F
I/O on RA6
microcontroller clock source, HS
Oscillator used as USB clock source
Internal Oscillator used as
microcontroller clock source, XT
Oscillator used as USB clock source
Internal Oscillator used as
microcontroller clock source, EC
Oscillator used as USB clock source,
digital I/O on RA6
microcontroller clock source, EC
Oscillator used as USB clock source,
F
OSC
devices, all core and peripheral clocks
/4 output on RA6
OSC
/4 output on RA6
OSC
DS39632D-page 23
/4 output