PIC18F2320-I/SO Microchip Technology, PIC18F2320-I/SO Datasheet - Page 27

• Manufacturer Part Number: PIC18F2320-I/SO
• Description: IC MCU FLASH 4KX16 EEPROM 28SOIC
• Manufacturer: Microchip Technology
• Series: PIC® 18Fr

Specifications of PIC18F2320-I/SO

• Core Size: 8-Bit
• Program Memory Size: 8KB (4K x 16)
• Core Processor: PIC
• Speed: 40MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, LVD, POR, PWM, WDT
• Number Of I /o: 25
• Program Memory Type: FLASH
• Eeprom Size: 256 x 8
• Ram Size: 512 x 8
• Voltage - Supply (vcc/vdd): 4.2 V ~ 5.5 V
• Data Converters: A/D 10x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 28-SOIC (7.5mm Width)
• Controller Family/series: PIC18
• No. Of I/o's: 25
• Eeprom Memory Size: 256Byte
• Ram Memory Size: 512Byte
• Cpu Speed: 40MHz
• No. Of Timers: 4
• Processor Series: PIC18F
• Core: PIC
• Data Bus Width: 8 bit
• Data Ram Size: 512 B
• Interface Type: SPI, I2C, USART
• Maximum Clock Frequency: 40 MHz
• Number Of Programmable I/os: 25
• Number Of Timers: 2 x 8 bit
• Operating Supply Voltage: 2 V to 5.5 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: 52715-96, 52716-328, 52717-734, 52712-325, EWPIC18
• Development Tools By Supplier: PG164130, DV164035, DV244005, DV164005, PG164120, ICE4000, ICE2000, DV164136
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 10 bit
• Package: 28SOIC W
• Device Core: PIC
• Family Name: PIC18
• Maximum Speed: 40 MHz
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: XLT28SO-1 - SOCKET TRANSITION 28SOIC 300MIL
• Lead Free Status / Rohs Status: Details

2.7
Like previous PIC18 devices, the PIC18F2X20 and
PIC18F4X20 devices include a feature that allows the
system clock source to be switched from the main
oscillator to an alternate, low-frequency clock source.
PIC18F2X20/4X20 devices offer two alternate clock
sources. When enabled, these give additional options
for switching to the various power-managed operating
modes.
Essentially, there are three clock sources for these
devices:
• Primary oscillators
• Secondary oscillators
• Internal oscillator block
The primary oscillators include the External Crystal
and Resonator modes, the External RC modes, the
External Clock modes and the internal oscillator block.
The particular mode is defined on POR by the contents
of Configuration Register 1H. The details of these
modes are covered earlier in this chapter.
The secondary oscillators are those external sources
not connected to the OSC1 or OSC2 pins. These
sources may continue to operate even after the
controller is placed in a power-managed mode.
PIC18F2X20/4X20 devices offer only the Timer1
oscillator as a secondary oscillator. This oscillator, in all
power-managed modes, is often the time base for
functions such as a Real-Time Clock (RTC).
Most often, a 32.768 kHz watch crystal is connected
between the RC0/T1OSO/T1CKI and RC1/T1OSI pins.
Like the LP Oscillator mode circuit, loading capacitors
are also connected from each pin to ground.
The Timer1 oscillator is discussed in greater detail in
Section 12.2 “Timer1 Oscillator”.
In addition to being a primary clock source, the internal
oscillator block 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 clock sources for the PIC18F2X20/4X20 devices
are shown in Figure 2-8. See Section 12.0 “Timer1
Module” for further details of the Timer1 oscillator. See
Section 23.1 “Configuration Bits” for Configuration
register details.
© 2007 Microchip Technology Inc.
Clock Sources and Oscillator
Switching
PIC18F2220/2320/4220/4320
2.7.1
The OSCCON register (Register 2-3) controls sev-
eral aspects of the system clock’s operation, both in
full-power operation and in power-managed modes.
The System Clock Select bits, SCS1:SCS0, select the
clock source that is used when the device is operating
in power-managed modes. The available clock sources
are the primary clock (defined in Configuration
Register 1H), the secondary clock (Timer1 oscillator)
and the internal oscillator block. The clock selection
has no effect until a SLEEP instruction is executed and
the device enters a power-managed mode of
operation. The SCS bits are cleared on all forms of
Reset.
The Internal Oscillator Select bits, IRCF2:IRCF0, select
the frequency output of the internal oscillator block that
is used to drive the system clock. The choices are the
INTRC source, the INTOSC source (8 MHz) or one of
the six frequencies derived from the INTOSC
postscaler (125 kHz to 4 MHz). If the internal oscillator
block is supplying the system clock, changing the
states of these bits will have an immediate change on
the internal oscillator’s output.
The OSTS, IOFS and T1RUN bits indicate which clock
source is currently providing the system clock. The
OSTS indicates that the Oscillator Start-up Timer
(OST) has timed out and the primary clock is providing
the system clock in primary clock modes. The IOFS bit
indicates when the internal oscillator block has stabi-
lized and is providing the system clock in RC Clock
modes. The T1RUN bit (T1CON<6>) indicates when
the Timer1 oscillator is providing the system clock in
secondary clock modes. If none of these bits are set,
the INTRC is providing the system clock, or the internal
oscillator block has just started and is not yet stable.
The IDLEN bit controls the selective shutdown of the
controller’s CPU in power-managed modes. The use of
these bits is discussed in more detail in Section 3.0
“Power-Managed Modes”.
Note 1: The Timer1 oscillator must be enabled to
2: It is recommended that the Timer1
OSCILLATOR CONTROL REGISTER
select the secondary clock source. The
Timer1 oscillator is enabled by setting the
T1OSCEN bit in the Timer1 Control regis-
ter (T1CON<3>). If the Timer1 oscillator
is not enabled, then any attempt to set the
SCS0 bit will be ignored.
oscillator be operating and stable before
executing the SLEEP instruction or a very
long delay may occur while the Timer1
oscillator starts.
DS39599G-page 25