PIC18F442-I/ML Microchip Technology, PIC18F442-I/ML Datasheet - Page 22

• Manufacturer Part Number: PIC18F442-I/ML
• Description: IC MCU FLASH 8KX16 EE A/D 44QFN
• Manufacturer: Microchip Technology
• Series: PIC® 18Fr

Specifications of PIC18F442-I/ML

• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 40MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, LVD, POR, PWM, WDT
• Number Of I /o: 34
• Program Memory Size: 16KB (8K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 256 x 8
• Ram Size: 768 x 8
• Voltage - Supply (vcc/vdd): 4.2 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: External
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 44-QFN
• For Use With: XLT44QFN2 - SOCKET TRAN ICE 44QFN/40DIPAC164322 - MODULE SOCKET MPLAB PM3 28/44QFN444-1001 - DEMO BOARD FOR PICMICRO MCU
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

PIC18FXX2
2.6
The PIC18FXX2 devices include a feature that allows
the system clock source to be switched from the main
oscillator to an alternate low frequency clock source.
For the PIC18FXX2 devices, this alternate clock source
is the Timer1 oscillator. If a low frequency crystal (32
kHz, for example) has been attached to the Timer1
oscillator pins and the Timer1 oscillator has been
enabled, the device can switch to a Low Power Execu-
FIGURE 2-7:
DS39564C-page 20
Oscillator Switching Feature
OSC2
OSC1
T1OSO
T1OSI
DEVICE CLOCK SOURCES
Timer1 Oscillator
Main Oscillator
PIC18FXXX
SLEEP
T1OSCEN
Enable
Oscillator
Clock Source option
for other modules
4 x PLL
tion mode. Figure 2-7 shows a block diagram of the
system clock sources. The clock switching feature is
enabled by programming the Oscillator Switching
Enable (OSCSEN) bit in Configuration Register1H to a
’0’. Clock switching is disabled in an erased device.
See Section 11.0 for further details of the Timer1 oscil-
lator. See Section 19.0 for Configuration Register
details.
T
T
T
OSC
1
P
T
OSC
/4
Source
Clock
© 2006 Microchip Technology Inc.
T
SCLK