MPC5643L datasheet(12/98 Pages) FREESCALE

12 / 98 page

MPC5643L Microcontroller Data Sheet, Rev. 3

Preliminary—Subject to Change Without Notice

Overview

Freescale Semiconductor

1.3.13

System clocks and clock generation

The following list summarizes the system clock and clock generation on this device:

•

Lock status continuously monitored by lock detect circuitry

•

Loss-of-clock (LOC) detection for reference and feedback clocks

•

On-chip loop filter (for improved electromagnetic interference performance and fewer external components required)

•

Programmable output clock divider of system clock (

÷1, ÷2, ÷4, ÷8)

•

FlexPWM module and as many as three eTimer modules running on an auxiliary clock independent from system clock

(with max frequency 120 MHz)

•

On-chip crystal oscillator with automatic level control

•

Dedicated internal 16 MHz internal RC oscillator for rapid start-up

— Supports automated frequency trimming by hardware during device startup and by user application

•

Auxiliary clock domain for motor control periphery (FlexPWM, eTimer, CTU, ADC, and SWG)

1.3.14

Frequency-Modulated Phase-Locked Loop (FMPLL)

Two FMPLLs are available on each device.

Each FMPLL allows the user to generate high speed system clocks starting from a minimum reference of 4 MHz input clock.

Further, the FMPLL supports programmable frequency modulation of the system clock. The PLL multiplication factor, output

clock divider ratio are all software configurable. The FMPLLs have the following major features:

•

Input frequency: 4–40 MHz continuous range (limited by the crystal oscillator)

•

Voltage controlled oscillator (VCO) range: 256–512 MHz

•

Frequency modulation via software control to reduce and control emission peaks

— Modulation depth ±2% if centered or 0% to –4% if downshifted via software control register

— Modulation frequency: triangular modulation with 25 kHz nominal rate

•

Option to switch modulation on and off via software interface

•

Reduced frequency divider (RFD) for reduced frequency operation without re-lock

•

Three modes of operation

— Bypass mode

— Normal PLL mode with crystal reference (default)

— Normal PLL mode with external reference

•

Lock monitor circuitry with lock status

•

Loss-of-lock detection for reference and feedback clocks

•

Self-clocked mode (SCM) operation

•

On-chip loop filter

•

Auxiliary FMPLL

— Used for FlexRay due to precise symbol rate requirement by the protocol

— Used for motor control periphery and connected IP (A/D digital interface CTU) to allow independent frequencies

of operation for PWM and timers and jitter-free control

— Option to enable/disable modulation to avoid protocol violation on jitter and/or potential unadjusted error in

electric motor control loop

— Allows to run motor control periphery at different (precisely lower, equal or higher as required) frequency than

the system to ensure higher resolution

1.3.15

Main oscillator

The main oscillator provides these features:

MPC5643L Datasheet(PDF) 12 Page - Freescale Semiconductor, Inc

MPC5643L Datasheet(HTML) 12 Page - Freescale Semiconductor, Inc

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98

Datasheet Download

Link URL