SPRUJH0B April   2025  – September 2025

 

  1.   1
  2.   Description
  3.   Get Started
  4.   Features
  5.   Applications
  6.   6
  7. 1Evaluation Module Overview
    1. 1.1 Introduction
    2. 1.2 Kit Contents
    3. 1.3 Specification
      1. 1.3.1 External Power Supply or Accessory Requirements
    4. 1.4 Device Information
  8. 2Hardware
    1. 2.1 Hardware Description
      1. 2.1.1 Functional Description and Connections
        1. 2.1.1.1 Power Domains
        2. 2.1.1.2 LEDs
        3. 2.1.1.3 Encoder Connectors
        4. 2.1.1.4 Boot Modes
        5. 2.1.1.5 BoosterPack Sites
        6. 2.1.1.6 Analog Voltage Reference
        7. 2.1.1.7 Other Headers and Jumpers
          1. 2.1.1.7.1 USB Isolation Block
          2. 2.1.1.7.2 Alternate Power
          3. 2.1.1.7.3 5V Step-up Converter
        8. 2.1.1.8 Programmable Gain Amplifier (PGA)
      2. 2.1.2 Debug Interface
        1. 2.1.2.1 XDS110 Debug Probe
        2. 2.1.2.2 Virtual COM Port
      3. 2.1.3 Alternate Routing
        1. 2.1.3.1 Overview
        2. 2.1.3.2 GPIO35/GPIO37 Routing
        3. 2.1.3.3 eQEP Routing
        4. 2.1.3.4 X1, X2 Routing
        5. 2.1.3.5 PWM DAC
    2. 2.2 Using the F28E12x LaunchPad
    3. 2.3 BoosterPacks
    4. 2.4 Hardware Revisions
      1. 2.4.1 Revision A
      2. 2.4.2 Revision E2
  9. 3Software
    1. 3.1 Software Development
      1. 3.1.1 Software Tools and Packages
      2. 3.1.2 F28E12x LaunchPad Demo Program
      3. 3.1.3 Programming and Running Other Software on the F28E12x LaunchPad
  10. 4Hardware Design Files
    1. 4.1 Schematic
    2. 4.2 PCB Layout
      1. 4.2.1 LAUNCHXL-F28E12X Board Dimensions
    3. 4.3 Bill of Materials (BOM)
  11. 5Additional Information
    1. 5.1 Frequently Asked Questions
    2. 5.2 Trademarks
  12. 6References
    1. 6.1 Reference Documents
    2. 6.2 Other TI Components Used in This Design
  13. 7Revision History

2.1.3.4 X1, X2 Routing

The F28E12x crystal oscillator output signal, X2, is multiplexed with GPIO18 and the crystal oscillator input, X1, is multiplexed with GPIO19. By default, the LaunchPad uses an on-board crystal oscillator, Y2, as the clock source for the on-chip Phase-Locked Loop (PLL) that requires both X1 and X2 signals of the MCU. To balance the requirement of having cleanly routed oscillator signals and bringing all possible GPIOs to the BoosterPack connectors, both GPIO18 and X2 and GPIO19 and X1 can be routed to the BoosterPack connectors through 0Ω resistors. If GPIO18 or GPIO19 are needed at the BoosterPack connectors, then the on-chip zero-pin oscillators must be used as the clock source for the on-chip PLL. For more information on the X1, X2 configurations, see the F28E12x Real-Time Microcontrollers data sheet.

If GPIO18 functionality is needed at the BoosterPack Connector:

  1. Remove R10 to separate GPIO18 from Y2.
  2. Populate R12 to connect GPIO18 to the BoosterPack connector

If GPIO19 functionality is needed at the BoosterPack Connector:

  1. Remove R11 to separate GPIO19 from Y2.
  2. Populate R13 to connect GPIO19 to the BoosterPack connector.