by:
NXP Semiconductors
1 Introduction
NXP’s MPC574xR is a dual-core 32-bit microcontroller intended for scalable
engine control and powertrain applications. This application note will refer to
any device in the MPC574xR family, MPC5743R, MPC5745R, and MPC5746R,
as simply “MPC5746R.”
The MPC5746R supports an 8-40 MHz external oscillator (XOSC), a 16 MHz
internal RC oscillator (IRCOSC), and two phase locked loops (PLL) for a
maximum operating frequency of 200 MHz. The IRCOSC is selected out of
reset so increasing the operating frequency from 16 MHz requires additional
configuration. The MPC574xR Clock Calculator is meant to complement the
reference manual. It seeks to simplify the clock configuration process by providing a graphical, interactive tool to help the user
find the correct register settings in order to achieve the desired clock frequencies.
Accompanying this application note is the clock calculator. You can download it from
.
The clock calculator makes use of macros to perform functions like resetting the spreadsheet to initial values, configuring all clock
frequencies to the maximum allowable settings, and copying generated code. Macros must be enabled in the user’s MS Excel to
access these features. If macros are turned off, however, the tool will still be able to calculate clock frequencies, but the
aforementioned features will be disabled. To turn on macros in MS Excel 2016, go to the
Developer
tab on the top toolbar and
click on
Macro Security
. A popup window will appear, select
Enable all macros
.
Figure 1. Enable macros
2 Clock calculator design
The MPC574xR clock calculator takes the form of an interactive Microsoft Excel spreadsheet organized into multiple tabs as shown
in the following figure.
Contents
1 Introduction..........................................1
2 Clock calculator design...................... 1
3 Clock tool example use sase:
Configure FlexCAN to XOSC at
40 MHz protocol clock and PLL0
50 MHz BIU/Module clock............... 14
4 Conclusion......................................... 26
5 Revision history.................................26
AN12020
MPC574xR Clock Calculator Guide
How to use MPC574xR tool to easily calculate device frequency domains
Rev. 5 — October 2018
Application Note
