MPC5510 Microcontroller Family Reference Manual, Rev. 1
Freescale Semiconductor
3-1
Preliminary
Chapter 3
System Clock Description
3.1
Introduction
The MPC5510 supports several clock sources that include an internal phase-locked loop (PLL), an
external high-frequency crystal (XOSC), an external low-frequency crystal (32kOSC), an internal
high-frequency RC oscillator (IRC), and an internal low-frequency RC oscillator (32kRC).
The availability of the clock sources vary, depending on the run, stop, and power mode selected. During
low power modes, the PLL and XOSC are not available as clock sources.
The internal system clock may be generated in several ways:
•
Internal 16 MHz IRC
•
PLL: Normal mode with crystal clock reference for XOSC
•
PLL: Normal mode with external clock reference for XOSC
•
XOSC with external clock reference (PLL bypass mode)
•
XOSC with crystal clock reference
There are two clock output pins driven by programmable clock dividers: CLKOUT and MCKO.
The oscillator clock can be selected as the clock source for the FlexCAN interface in the FlexCAN blocks
resulting in very low jitter performance. The oscillator clock can also be selected as the clock source for
the FlexRay interface in the FlexRay block.
The default clock source after reset is the 16 MHz IRC.
3.2
Clock Sources
The various clock sources that are available on MPC5510 are shown in
detail in subsequent sections.
