MCU 101: Technical Documentation

[#1]

Sifting through technical documentation is part of an engineers job.  Sometimes these documents can be hundreds or thousands of pages long, so knowing where to makes life much easier.  This article is going to try to help you navigate smarter...

Freescale has the following structure for technical documents:

• Reference Manuals (Usually end with "RM") - These are typically the thick manuals.  You will find sections detailing operation, registers, and electrical characteristics.
• Data Sheet (Usually ends with "DS") - These are quick summaries of the specifications of the device.  Includes electrical characteristics such as operating voltages, input and output minimum and maximum ranges.  In addition to environmental characteristics such as temperature ranges and graphs of performance vs. certain conditions.
• Schematic (_SCH) - This is typically referred in terms of board designs.  A schematic is useful in finding out how and where an external thing (LED, button, Display) is connected to the microcontroller. 
• Fact Sheet (_FS) - This is generally overview type information.  Useful when you are trying to determine which microcontroller you want to use. 
• Errata - Sometimes there are bugs in the chip.  When these are discovered the company issues an errata.  Sometimes the item get's fixed in the next revision of the chip, sometimes you just work around the problem.  If you think it should be working and it's not check the erratas!
  

Tips and Tricks

• Use the search or find function all the time. Shortcut key '''(Ctrl-F).'''
• Use two monitors. Have the document open in one, search or browse to what you need to find and simply copy and paste the configuration information into your IDE.
• Search tips:  Use the pin name.  (I.e. PTC, PORTA, or FTM)
• Save trees only print out what you need.
  

Commonly Used Acronyms:

• PDB - Programmable Delay Block
• FTM - Flex Timer Module
• ADC - Analog to Digital Converter
• DAC - Digital to Analog Converter
• MCG - Multipurpose Clock Generator
• SPI - Serial Programming Interface
• CnV - Channel n Value
• CNTIN - Counter Initial Value
• SIM - System Integration Module
• SIM_SCGCn - System Integration Module, System Clock Gating Control Register
• CMP - Comparator Module
• SIM - Provides system control and chip configuration registers. You will use this to turn on the clocks to particular peripherals. The SIM_SCGC