PIC32MX440F256H-80I Datasheet, PDF (12/646 Pages) Microchip Technology – 64/100-Pin General Purpose and USB 32-Bit Flash Microcontrollers

PIC32MX3XX/4XX
1.6 External Interface
A Parallel Master Port Parallel Slave Port enables 8/16-
bit parallel data communications in Master mode with
up to 16 address lines; 8-bit Slave modes are also
supported.
1.7 Real-Time Clock/Calendar
This module implements a full-featured clock and
calendar with alarm functions in hardware, freeing up
timer resources and program memory space for use of
the core application.
1.8 Oscillator Options and Features
All of the devices in the PIC32MX family offer four
different oscillator options, allowing users a range of
choices in developing application hardware. These
include:
• A Primary Oscillator (POSC) with two External
Crystal modes using crystals or ceramic
resonators.
• Two External Clock modes with selectable
peripheral bus clock output.
• A Fast Internal Oscillator (FRC) with a nominal
8 MHz output.
• On-board postscalers and/or PLL to provide clock
speeds ranging from 31 kHz to maximum
specified frequency.
• A Secondary Oscillator (SOSC) designed to
operate with an external 32.768 kHz crystal. This
oscillator can also be used with Timer1 and the
integrated RTCC.
• An Internal Low-Power RC oscillator (LPRC)
having a fixed 31 kHz output, which provides a
low-power option for timing-insensitive
applications.
The oscillator block also provides a stable reference
source for the user-controlled Fail-Safe Clock Monitor.
This option constantly monitors the main clock source
against a reference signal provided by the internal
oscillator and enables the controller to switch to the
internal oscillator, allowing for continued low-speed
operation or a safe application shutdown.
DS61143E-page 10
Preliminary
© 2008 Microchip Technology Inc.